A B C D E F G H I J K L M N O P Q R S T U V W X Z

Abortive Only partially developed, such as incomplete seed or frost-nipped bud.

Abscission The falling of leaf, twig-tip, etc, from a clean-cut scar, by a self-healing wound.

Accent plant Attention-getting plant due to its color or form.

Accessory buds Buds found beside or above the true bud at a node.

Achene A dry, one-seeded fruit.

Acid soil A soil with a pH lower than 7.0 is an acid soil. pH is a measure of the amount of lime (calcium) contained in your soil.

Acre A measure of land totaling 43,560 square feet. A square acre is 208.75 feet on each side.

Aculeate Prickly.

Acuminate Having a sharp, gradually tapered point.

Adult phase the stage of plants capable of producing fruit and flowers.

Adventitious Not in the usual place.

Adventious bud an extra or special bud not found in the axil of a leaf.

Aerate Loosening or puncturing the soil to increase water penetration.

Aerial roots Roots produced above ground, often used for climbing.

Aggregated Joined together, confluent, as applied to bundle traces.

Aggregate flower A single flower heaped or crowded into a dense flower cluster.

Aggregate fruit A fruit formed by the coherence or the connation of pistils that were distinct in the flower.

Air layering A specialized method of plant propagation accomplished by cutting into the bark of the plant to induce new roots to form; a process of producing a new plant by forming soil around a stem.

Alba/albus/album White or whitish, usually applied to flowers

Albo-maculata Spotted in white.

Albo-marginata White edged or margined.

Albo-striata striped or striated in white. Usually a variegated plant.

Alkaline soil A soil with a pH higher than 7.0 is an alkaline soil. pH is a measure of the amount of lime (calcium) contained in your soil.

Alpina/alpinus/alpinum Epithet meaning from an alpine area or just a very dwarf plant. It is also used to denote smaller species in a large genus.

Alpine Any plant that is normally found in wild on mountains or in mountainous areas.

Alt Latin prefix meaning tall.

Alternate Said of leaf scars or leaves occurring one at each node.

Altissima Tall.

Amplexicaul Encircling the stem.

Anatomy The internal structure of plant.

Anchor root A large root that holds a plant in a physical soil mass.

Androecium Stamens of a flower, as a unit.

Annual A plant that germinates, grows, flowers, produces seeds in one growing season.

Annual ring A concentric circle of wood produced by one year’s growth in a tree trunk.

Annuals Plants whose life cycle lasts only one year, from seed to blooms to seed.

Anther The pollen-bearing portion of a flower; a male part.

Anthracnose A fungus disease that causes spots and often death of foliage.

Aquatic plants Plants that grow in, or live in or on water.

Arboretum Organized collection of trees and other woody plants; a garden with a large collection of trees and shrubs cultivated for scientific or educational purposes.

Arboriculture The science of the culture or care of trees.

Arborist A certified/licensed tree doctor specialist.

Arcuate Arched, bent like a bow.

Aril A fleshy appendage of the seed, usually a fleshy seedcoat.

Aromatic Fragrantly scented, especially when broken or crushed.

Articular A membrane consisting of the thin, enlarged base of the petiole, on which the leaf scar occurs.

Articulate Having nodes or joints where separation may naturally occur.

Annular Ring-like; said of leaf scars that encircle the bud, or bundle scars that are circular with an opening in the center.

Anterior On the front side, away from the axis, toward the subtending bract.

Anther The pollen bearing part of a stamen, borne at the top of a filament or sessile.

Apetalous Without petals.

Apex The tip or terminal end.

Aphid a small green or white insect that sucks juices from plant parts

Apical Describes the apex or tip.

Apiculate Ending in an abrupt pointed tip.

Apomixis process of producing viable seed without fertilization

Appressed Flattened against the twig; not spreading.

Arborcide a type of herbicide chemical that kills trees.

Arboreal Tree-like or pertaining to trees.

Arborescent Tree-like; defined arbitrarily as pertaining to a woody plant at least 20 feet high in maturity with a single stem and more or less definite crown.

Ascending Curving indirectly or obliquely upward.

Asexual propagation multiplying plants without use of seeds

Attenuate Showing a long gradual slender taper; usually applied to apices, but equally appropriate for bases of leaves, petals, etc.

Atro- Botanical name prefix meaning dark or intensely colored.

Atrosanguinea Dark or blood red or maroon.

Atrovirens Dark or blackish green.

Aurescent Becoming yellow or yellow part of the season.

Auxin A chemical that stimulates plant growth.

Awn A bristle-like appendage.

Axil The angle between a petal and a stem; where buds occur above a leaf; the point above a leaf scar.

Axillary In the axil.

Axis The main stem or central support of a plant.

Azurea/azureus/azureum Azure or deep blue.

B & B Balled and burlapped, a method of digging and holding woody plants.

Baccate Pulpy, fleshy.

Backcross A hybrid of two plants crossed once again back to one parent.

Barbed Bristles With terminal or lateral spine-like hooks that are bent sharply backward.

Bareroot Said of plants with the soil removed from their roots; not shipped in pots or with a full root ball.

Bark The rough outer part of the cortex; loosely used for the entire cortex.

Basal Pertaining to the extremity of an organ by which it is attached to its support; leaves located at the base of the plant only.

Beaked Ending in a point, especially on fruits.

Beard Patch of hairs on a flower or other part

Bi- Prefix meaning twice or doubly.

Bicolor A plant or flower in two colors.

Biennial A plant that usually only lives two years, normally producing flowers and seed the second year; a plant that grows foliage the first year and flowers the second year.

Bifida/bifidum Divided into two parts.

Bifurcate Forked, Y-shaped.

Bigeneric hybrid Species formed by crossing two different genera.

Biomass Substance of living tissue, often a measure of weight or volume.

Bipinnate Twice compound with the leaflets along each side of a common axis. The leaflets are further divided into pinnules.

Bisexual Said of a flower with both stamens and pistils.

Blade The expanded part of a leaf.

Blush Pink or reddish tint to a plant part

Bloom A waxy coating sometimes found on stems, leaves, flowers and fruits.

Bole The stem of a tree.

Bolting Vegetables quickly flowering rather than producing the food crop. Usually caused by late planting and too warm temperatures.

Bonsai A living woody plant dwarfed by careful pruning and container culture.

Botanical name The Latin or scientific name of a plant, usually composed of two words, the genus and the species.

Bottom heat The undersurface heat provided in the soil by electric cables or hot water pipes.

Bract Leaf-like or petal-like structure, which may appear with or below flowers, or have a bright flower-like appearance.

Bristly With stiff hairs.

Bronzing A metallic bronze or coppery color, especially of foliage after a winter.

Bud The rudimentary or resting end or branch of a stem; usually referring to the stage in which the growing tips pass the winter or dry season; also applied to undeveloped flowers or flower clusters. A dormant growth point that is usually covered by scales.

Bud count Number of early buds.

Bud eye A potential growth point that is used for budding.

Bud scale A modified leaf or stipule (there may be one, a few, or many) protective of the embryonic tissue of the bud.

Bud union A swollen and distinct node when a bud has been grafted.

Bulb The thickened underground storage organ of the group of perennials which includes daffodils and tulips. A modified underground stem comprised of shortened central axis surrounded by fleshy scale-like leaves.

Bulbil Small bulbs arising around the parent bulb.

Bulblet Small bulbs arising in the leaf axils.

Bundle scar Small dots or lines on the surface of the leaf scar marking the point of original departure of the vascular conducting strands into the leaf. Also called bundle trace.

Bur Any rough or prickly seed envelope.

Burl A knot or woody growth of very irregular grain.

Butterfly garden Planting to attract, feed and support Lepidoptera.

Button center A double rose flower with unexpanded central petaloid parts.

Buttressed With supporting wings.

Caducous Falling away early or prematurely.

Caerulea/caeruleum/caeruleus Intensely blue.

Calcarate Having a spur.

Calcium nitrogen A quick-acting fertilizer with about 48% calcium and 16% nitrogen.

Callus A thickened tissue that develops at the base of stem cuttings; new tissues formed in response to a wound.

Calyx Sepals and often greenish bracts underneath a flower; the outer floral envelope. The outer set of perianth segments, usually green in color and smaller than the inner set.

Cambium The thin membrane located just beneath the bark of a plant.

Campanulata Latin name for a plant having campanulate or bell-like flowers.

Campanulate Bell-shaped

Cane Stem from a thin multi-stem plant; a long woody pliable stem rising from the ground.

Canescent Ash-colored, with gray hairs.

Canker Bacterial or fungal disease causing bark lesions

Capillary Hair-like; very slender.

Capitata Latin name for a plant with a head-like or large clustered feature.

Capitate Headlike, in a dense rounded cluster.

Capsule A dry fruit holding many seeds and coming from two or more carpels; a dry fruit derived from a compound pistil.

Cardinalis/cardinale Bright glowing red.

Carpel A single pistil in a female flower part containing several pistils

Caryopsis The fruit of members of the grass family.

Castaneous Dark brown.

Catkin A single-sex spike with no petals; a slender, spikelike, drooping flower cluster. A spike-like inflorescence comprised of scaly bracts subtending unisexual flowers.

Caudiform A plant with a fleshy swollen base that is not a true bulb.

Caulescent Having an evident leaf bearing stem above ground.

Cauliflorous Flowering on the trunk or on specialized spurs from it or from the larger branches.

Cellar gardening Using a basement to grow plants with artificial light.

Ceriferous Waxy.

Cernuous Drooping or nodding.

Certified/certification Seed or stock verified to be true or lacking viruses.

Chalk white limestone product or soil.

Chambered Said of pith when divided into small, empty compartments separated by transverse partitions; with cavities separated by plates or disks.

Channeled Grooved lengthwise.

Chaparral A collective Western USA planting of scrubby underbrush.

Charcoal A soil additive to increase moisture intake.

Chimera/chimaera A fusion of unrelated tissues such as in all variegated leaves; a man-made fusion of tissue caused by grafting.

Chlorophyll A group of green molecules used to convert light to energy.

Chlorosis The yellowing of plant tissue due to nutrient deficiencies or disease.

Chromosome A unit of heredity material in all living cells.

Ciliate With short fine hairs as on a leaf or petal margin.

Clasping A stalkless leaf, with the base partly surrounding the stem.

Claw The constricted petiole-like base of petals and sepals of some flowers.

Clean cultivation Gardening practice of removing all weeds at all times.

Cleft Divided to or about the middle into divisions.

Cleistogamous A small, closed self-fertilized flower, usually near the ground.

Climber A vine-like or rambling plant that raises its foliage by supporting itself on surrounding objects, either by twining or coiling around them, by the aid of tendrils or aerial roots, or by scrambling over them.

Clinal variation/cline With a spectrum such as blue to green in spruces,

Clone A line of plants propagated from a single mother plant, identical to each other and to the parent.

Club root A fungal disease causing swollen roots.

Clustered Said of leaves, crowded so as not to be clearly opposite or alternate, also said of the whorled condition.

Coccinea/coccineus/coccineum Scarlet red or bright red.

Colchicine A toxic chemical used to double chromosome numbers in seeds.

Cold frame A low frame with clear top used to acclimatize plants to, or protect them from, cold.

Collateral Said of extra or supernumerary buds that are inserted on either side of a normal axillary bud. Said of buds that grow side by side.

Comose Tufted with hairs.

Companion plant A plant making an showy, contrasting display or providing pollination

Complete fertilizer A plant food with all three of the primary elements: nitrogen, phosphorus and potassium.

Complete flower One that has corolla, calyx, stamens and one or more pistils.

Compost An organic soil amendment resulting from the decomposition of organic matter.

Compound leaf A leaf of two or more leaflets, in some cases the lateral leaflets may have been lost and only the terminal leaflet remain.

Compressed Flattened from the sides, as applied to nodes or buds.

Cone A coniferous fruit, having a number of woody, leathery, or fleshy scales, each bearing one or more seeds, and attached to a central axis; the seed-holding structure of trees like pines and spruce.

Conifer A cone-bearing plant, with tiny needlelike leaves, that may be evergreen or deciduous.

Coniferous Cone bearing.

Continuous Said of pith which is solid; not spongy, chambered or interrupted by cavities.

Coppice growth Arising from sprouts at the stump; bushy.

Cordate Heart-shaped.

Cordiform Heart-shaped or formed.

Cordoned Having been espaliered.

Corky Soft and springy.

Corm Fleshy underground stem that resembles a true bulb, which produces roots, leaves and flowers during the growing season.

Cormel A tiny corm (fleshy stem base) around a large mother corm.

Cornuta/cornutum/cornutus Epithet meaning horned.

Corolla The petals and normally colored portion of a flower; the inner floral envelope, consisting of petals.

Corona/crown A fused flower tissue as in the cup of a Daffodil; the point at which a plant’s roots and top join.

Cortex The rind or outer covering of a stem; technically it lies outside of the vascular bundles, which constitute the stele.

Corymb A more or less flat-topped indeterminate inflorescence whose outer flowers open first.

Cotyledon The primary leaves of the embryo, present in the seed.

Cover crop A crop that is planted in the absence of the normal crop to control weeds and add humus to the soil when it is plowed in prior to regular planting.

Creeping Growing and spreading over the ground.

Crenate Scalloped; with rounded teeth.

Crenate-serrate Having a mixture of blunt and sharp teeth.

Crenulate Finely crenate.

Creosote An oil-based preservative used to treat wood used in gardens.

Crisped Wavy on the margin; short and curly when applied to pubescence.

Crown The part of a budded plant when the scion and understock meet.

Crucifer A member of the Mustard family.

Cruciform Cross shaped.

Cryptogam A plant reproducing by spores such as most ferns and algae.

Cucullate Hooded.

Culm An upright flowering stem from a rhizome; stem of grasses and sedges.

Cultigen Any plant arising from cultivation and not the wild.

Cultivar A cultivated variety; does not occur naturally.

Cultivar group An association of related cultivars with a species, subspecies, or variety due to common origin or groups of traits.

Cuneate Wedge-shaped.

Cupped A flower with depressed or concave center.

Cuticle The outermost layer of epidermal cell walls.

Cuttage The process of rooting cuttings.

Cutting Any stem or vegetative part of a plant used for propagation.

Cymbiform Boat shaped.

Cyme A more or less flat-topped determinate inflorescence whose outer flowers open last.

Cytology The study of cells and often chromosomes.

Damping off Decay of young seedlings at ground level following fungal attack. Often the result of soil borne diseases or over watering.

Deadheading The processing of removing old or spent flowers to prevent them from setting seed. This will promote continued bloom.

Decidua A deciduous species in a normally evergreen genus.

Deciduous A plant that loses its leaves in the autumn; falling or not persistent as in maple or oak trees each fall; leaves or stipules which do not persist in a green condition throughout the winter.

Decompound Repeatedly compound.

Decumbent Reclining on the ground with the tip ascending; trailing stems on the ground with lateral shoots upright

Decurrent Continued down the stem in a ridge or wing, as applied to leaf-bases.

Defoliate/defoliation Loss of leaves such as premature summer leaf drop; casting off or falling off of leaves.

Dehiscent Opening to discharge the seeds or pollen.

Deliquescent Breaking up into fine branches.

Deltoid Triangular, with equal sides.

Dense Crowded together, thick, compact.

Dentate Having marginal teeth whose apices are perpendicular to the margin and do not point forward.

Denuded Naked through the loss of covering.

Determinate Said of an inflorescence when the terminal flower opens first and the prolongation of the axis is thereby arrested.

Dethatch Process of removing dead stems built up beneath lawn grasses.

Di- A prefix meaning two.

Diaphragmed Said of pith which is solid with transverse bars of denser tissue at intervals between the nodes or at the nodes.

Dibble A stick or tool that makes planting holes in soil or media.

Dichotomous Forked in pairs.

Dicot A plant of the angiosperm group having two cotyledons.

Dieback Death of shoot tips such as by winter cold or chemical damage.

Diffuse Loosely or widely spreading, an open form.

Digitate Spreading like the fingers, the leaflets leaving the petiole at one point as applied to compound leaves. The same as palmate.

Dimorphic Having two forms.

Dioecious A species having unisexual flowers, each sex confined to a separate plant.

Diploid Having two set of chromosomes.

Direct seeding Germination of seed in their final spot as opposed to in a nursery.

Disarticulating Falling away by abscission, leaving a clean cut scar, as with most leaves, many flowers, some twig tips, etc.

Disbudding The processing of removing extra buds to promote larger flowers.

Discoid The same as chambered, when applied to pith.

Disease A fungus or virus infection.

Disk An enlarged tip, as applied to tendrils.

Disk flower The tubular flower in the center of the usual Compositae inflorescence.

Dissected Cut, lacerated or divided in narrow, slender segments, said of fringed petals or leaves.

Dissectum Deeply cut, as in foliage.

Distal Toward the apex, away from the base.

Dish garden A miniature planting in a shallow tray.

Display index Percentage of peak display for flowers or other showy part.

Distichous Two ranked.

Diurnal blossoms Opening only during the day.

Divaricate Spreading very wide apart.

Divergent Spreading.

Divided Deeply lobed when applied to leaves; separated to the base into divisions.

Dividing/division A method of propagating plants by separating each one into two or more sections and then replanting.

Domestica A plant having been domesticated or cultivated near residences.

Dormancy A state of suspended growth; the yearly cycle in a plant’s life when growth slows and the plant rests.

Dorsal Relating to the back or outer portion of a plant part; of or on the back or outer surface of a leaf.

Double A flower with numerous and full petals.

Double digging Soil bed preparation done by two or more spading sessions, preparing the soil by systematically digging an area to the depth of two shovels.

Double nose Said of bulbs with two growing apices.

Doubly serrate Serrations bearing minute teeth on the margins.

Downy With soft short straight hairs.

Drip irrigation Watering plants by small droplets over a long period of time each day.

Drip line The circle which would exist if you drew a line below the tips of the outer most branches of a tree or plant.

Drupe A stone-bearing fruit, such as a plum.

Dwarf Said of a genetically smaller plant, often 1/4 or less normal size.

Edging plant A compact, short plant used to line or trim borders.

Edible landscape A landscape planted with vegetables and fruit plants.

Ellipsoid Elliptical in section, like a football.

Endangered species A species likely to become extinct.

Endemic Native or local to an area.

-ensis Botanical name suffix meaning from a region or country.

Entire Neither toothed nor lobed, as applied to leaves.

Ephemeral Persisting for one day only, of short duration.

Epidermis Outer skin of the twig; sometimes peeling or cracking during the first winter; ultimately destroyed by growth in diameter of the twig.

Epiphyte A plant that grows in the air or on another plant but gets its nourishment from the air and rainfall. A plant growing on another without being a parasite or on a rock or tree trunk.

Erect Upright habit of growth.

Erosion The wearing away, washing away, or removal of soil by wind, water or human activity.

Espalier Process of training a tree or shrub so its branches grow in a flat pattern.

Ethylene Naturally occurring gas to ripen fruit.

Etiolation Stretching of a plant and loss of color due to a lack of needed light.

Escape A garden plant that has been seeded or spread into the wild.

Espalier Any plant trained lattice fashion in one plane; woody plant trained in a lattice-like or fence-like pattern on some support.

Evergreen Holding or having green foliage through the winter.

Everlasting A flowering plant that retains colors when cut and dried.

Evaporation Process by which water returns to the air.

Evapotranspiration Process of loss of water from a plant's tissue and soil.

Excavated Hollowed out, as applied to pith, making the stem fistulous.

Exfoliating Peeling away; bark that peels and sheds off.

Exotic Said of a plant not native; rare or tropical plants.

Explant Any removed portion of a plant used for tissue culture.

Exserted Projecting beyond, as stamens beyond a corolla.

Extra-axillary Above rather than in the axil. Same as supra-axillary.

Eye An undeveloped bud growth which will ultimately produce new growth; a vegetative or leafy bud.

F1 hybrid/f1 hybrid A first generation of a cross of different plants.

Falcate Sickle shaped.

Falls The outer whorl of petals of an iris flower, often broader than the inner petals and often drooping or flexuous.

Fasciated Much flattened or cockscomb-like growth; seemingly several units fused together.

Fascicled Clustered.

Fastigiate With upright branches; having a narrowly columnar or pillar-like growth form.

Flat A shallow box or tray used to start cuttings or seedlings.

Feathering Spreading out roots before planting a potted plant.

Fertile Capable of producing seed.

Fertilizer Organic or inorganic plant food used to amend the soil in order to improve the quality or quantity of plant growth.

Fiddlehead An unfurling fern frond that resembles the end of a violin.

Filament The slender stalk or stem of the anther or pollen sac.

Fireblight A serious bacterial disease that kills members of the rose family.

Fibrous Having long narrow shreds or flakes.

Filimentous Thread-like.

Filiform Thread-like, long and very slender.

Fissured Torn lengthwise, in vertical furrows, as applied to bark, or to pith, for which the more general term spongy is used.

Fistulous Hollow, with excavated pith.

Flaking Shredding, but with short segments.

Fleshy For a stem, not hard and woody; for a fruit or bud scales, not dry. Succulent.

Floret Technically a minute flower; applied to the flowers of grasses and Composites.

Floriculture The study of producing and marketing fresh flowers.

Florida With abundant flowers.

Floriferous Having many flowers compared to most cultivars or species.

Fluted Grooved.

Foliage Leaves.

Foliar Of or concerning foliage or leaves

Follicle A small dry fruit opening down one edge.

Focal plant A plant with form or color calling attention or focus to an area.

Foliar feeding Fertilizer applied in liquid form to the plants foliage in a fine spray.

Forcing The process of hastening a plants growth to maturity or bloom, stimulation of flowers or growth by controlling light and temperature.

Form A botanical variation of a variety differing in only one trait, such as color. A subdivision of species that occurs occasionally in the wild, seldom breeds true, and does not develop a natural population or distribution.

Foundation plant A plant suitable for planting around houses and below windows.

Fragmented Not continuous, as applied to bundle scars.

Fringed Ciliate with glands or scales rather than fine hairs.

Frond The term used to describe the branch and leaf structure of ferns or palms.

Fruticose/fruticosa/fruticosum/fruticosus Shrubby or shrub-like, in the sense of the stems being woody. Often in a genus of smaller form.

Fumigation Use of gas or vapors that sterilize soils or containers

Fungicide A chemical used to kill fungus, ills, diseases or viruses.

Fusiform Spindle-shaped; tapering to each end from a smaller mid-section.

Gall A swelling on a leaf or stem caused by fungi or insects like wasps.

Genotype The true genetic makeup of a plant.

Genus A group of species possessing fundamental traits in common but differing in other lesser characteristics.

Germinate The process of a seed sprouting.

Germination Development of seeds into seedlings or leafy young plants; the first stage in the development of a plant from seed.

Gibberellin A group of compounds that naturally control stem elongation.

Girdle To intentionally remove bark for grafting or to kill a plant. The choking of a branch by a wire or other material, most often in the stems of woody plants that have been tied to tightly to a stake or support.

Girdling Root Roots that strangle a plant by encircling it tightly.

Glabrate Nearly glabrous.

Glabrescent Becoming smooth.

Glabrous Smooth.

Gland Secreting organ. A pore or hair that release liquid or air.

Glandular-bristly With stiff gland-tipped hairs.

Glandular-ciliate Fringed with small glands.

Glandular-pubescent With gland-tipped hairs.

Glauca/glaucum/glaucus Covered with a white or bluish waxy bloom.

Globose Shaped like a globe; spherical.

Glossy Shining, reflecting more light than if lustrous.

Graft Inserting a bud or stem into another plant for purposes of propagation.

Grafting wax A wax used to seal a bud or graft from water and air.

Grandiflora/grandiflorus/grandiflorum Epithet meaning larger flowers than normal for a species; a class of roses with large and clustering blooms.

Green fertilizer/manure A fast-growing crop used to add organic matter when plowed under.

Growth habit General appearance or mode of growth.

Grafting The process of joining a stem or bud of one plant on to the stem or root stock of a different plant.

Ground cover A group of plants usually used to cover bare earth and create a uniform appearance; a spreading short plant used to cover soil; a living mulch.

Growing media/growing medium A material used to culture plants.

Growing season The number of days between the average date of the last killing frost in spring and the first killing frost in fall

Growth regulator A chemical used to increase growth or shorter stems.

Guano Bat or bird dropping used as a fertilizer high with about 13% nitrogen.

Habit Growth form or overall plant shape.

Habitat Type of region in which a plant is native.

Ha-ha Hidden ditch used to keep out people or animals.

Halophyte Salt-loving or salt-tolerant plant.

Half- or sub-shrub A plant with stems that are woody at the base, usually dying back to the woody stems or even back to the ground after severe winters.

Hardened A plant condition created by various factors enabling it to withstand environmental stresses.

Hardening off The process of gradually acclimatizing greenhouse or indoor grown plants to outdoor growing conditions.

Hardiness/Hardy The ability of a plant to withstand low temperatures or frost, without artificial protection.

Hardpan The impervious layer of soil or clay lying beneath the topsoil.

Hardscape Constructed elements of a landscape such as decks, walls fences and driveways. Structures and features of a landscape constructed from materials other than plants, such as walks, walls, and trellises made of wood, stone, or other materials, pathways, pools and ponds.

Hardwood A deciduous tree.

Hardwood cutting A cutting taking from mature or lignified stems.

Harvesting The removal of a desirable plant part.

Heading back Cutting an older branch or stem back to a stub or twig.

Healing The process of closing of a plant wound or graft union.

Heaving Lifting of soil and plants due to frost and ice.

Hedge A linear planting of plants as a barrier.

Heeling in Temporarily setting a plant into a shallow trench and covering the roots with soil to provide protection until it is ready to be permanently planted.

Heirloom Any open-pollinated plant that has a history of domesticity and that has been grown for at least 50 years.

Heliotropic A plant that responds to sun or light.

Herb Any fleshy plant. Used mostly to denote edible aromatic ones. A plant dying to the ground at the end of the season; one whose aerial stems are soft and succulent.

Herbaceous Plants that die down in winter and sprout forth the following spring; a plant with soft or succulent tissue.

Herbarium A collection of pressed and dry specimens for research purposes.

Herbicide A chemical used to kill specific plants or all plants in its path.

High centered Having petals taller or more pointed than outer petals.

Hip Fruit of a rose.

Hippocrepiform Horseshoe-shaped.

Hirsute Hairy; with hairs.

Hoary White or whitish.

Honeydew The sticky secretion produced by sucking insects such as aphids.

Horizontalis/horizontale Having habit or branches very horizontal; branches spreading outward rather than being erect.

Horticulture The science and art of growing fruit, flowers, ornamental plants, and vegetables in gardens. The cultivation of flowers, fruits, vegetables and ornamental plants.

Hortus Latin word for garden.

Hotbed A heated soil bed used for propagation as with cuttings in winter.

Humus The rich, brown or black organic part of the soil resulting from the partial decay of leaves and other matter.

Husk Outer covering of a fruit or seed.

Hybrid The offspring of two plants of different species or varieties of plants. Hybrids are created when the pollen from one kind of plant is used to pollinate and entirely different variety, resulting in a new plant altogether. Hybrid seed will not be true therefore it isn't suitable for seed saving.

Hydroculture Long-term plant growing in water-based nutrient solutions.

Hydroponics The science of growing plants in mineral solutions or liquid, instead of soil.

-iana Suffix meaning commemorative, or in memory of.

IAA Indole-3-acetic acid; used to promote rooting in cuttings.

IBA Indolebutyric acid; used to promote rooting in cuttings.

-ii Suffix on plant names honoring the person who found it.

Imbricate Scales that overlap like shingles; the opposite of valvate in which the scales meet along a line without overlapping.

Incised Cut by sharp and irregular incisions more or less deeply, but intermediate between toothed and lobed.

Included Not protruding as stamens not projecting beyond a corolla; as opposed to exserted.

Incomplete flower One which lacks any one or more of these parts; calyx, corolla, stamens, and pistils.

Indehiscent Not opening, as applied to fruits.

Indeterminate Said of those kinds of inflorescence whose terminal flowers open last, hence the growth or elongation of the main axis is not arrested by the opening of the first flowers.

Indurate Hardened.

Inequilateral With unequal sides.

Inflorescence A flower cluster.

Infra Below.

Imperfect flower A flower that lacks either stamens or pistils.

Imposter clone A clone that has incorrectly replaced the true clone in the trade.

Inarching A type of grafting that attaches a parent plant using an arched stem.

Inbred/inbreeding An undesirable plant made by crossing two related plants.

Indicator plant A sensitive plant that alerts to some condition such as drought.

Inermis Without thorns or less thorny.

Inorganic Something that was never alive; of human manufacture.

Internode The stem space between leaf or flower nodes.

Interspecific Between species; hybrid cross.

Interstem/interstock A piece of stem tissue grafted between a rootstock and a scion.

Introduced A plant that is exotic or brought from another region; a plant brought and sold in the nursery trade for the first time.

Involucrate With an involucre or cluster of bracts.

Involucre A cluster of modified leaves about a flower cluster.

Japonica/japonicus/japonicus Epithet meaning from Japan; such plants are widely Asian

Jointed Having nodes or points of real or apparent articulation.

Juvenile An early non-reproductive phase of plant growth, usually characterized by different leaf shapes or by non-flowering, vigorous increase in size, and often thorniness.

Keel A ridge on the back of a leaf or bud scale; fused boat-shaped petals in members of the pea family.

Key A small indehiscent fruit with a wing.

Knees bent projection of trunk; pointed or dome-like outgrowths such as those at the base of a bald cypress from cypress roots rising above the water.

Labiate Having lips as in the two lips in flowers in the mint family

Lacebark With exfoliating or bi-colored bark, usually with a fine texture.

Lacinate Cut or dissected as in leaf margins or some lacy flower petals.

Lactiflora/lactiflorus/lactiflorum White or milky-colored.

Lactiferous Milky.

Lanceolate Shaped like a lance-head.

Larva Immature insects such as caterpillars.

Lateral Said of buds which appear along the sides of the twig; at or along the side.

Lateral bud A bud borne in the axil of a previous season’s leaf.

Lath An overhead structure of evenly spaced slats of wood or other materials used to create shade.

Lathhouse A shaded environment created using slats of wood.

Latifolia Epithet meaning wider leaves than normal for a genus or species.

Latiloba/latilobus/latilobum Epithet meaning wider lobes or tissues sections in a leaf or flower.

Lawn Any expansive planting of grass, mowed to keep it short.

Layering A method of propagation, by which a branch of a plant is rooted while still attached to the plant by securing it to the soil with a piece of wire or other means; propagation method to root attached portions of side shoots.

Leaching The removal or loss of excess salts or nutrients from soil. The soil around over fertilized plants can be leached clean by large quantities of fresh water. Areas of extremely high rainfall sometimes lose the nutrients from the soil by natural leaching.

Leader The primary or terminal shoot; the trunk of a tree.

Leaflet Flat division of a leaf; one of the divisions of a compound leaf.

Leaf mold Partially decomposed leaf matter, used as a soil amendment.

Leaf scar Mark on a twig or stem left where a leaf was detached.

Leafspot One of many types of fungal or bacteria diseases causing round marks.

Leggy Abnormally tall and spindly growth; a lot of stem space between leaves.

Legume A pod; the characteristic fruit of the pea family.

Lenticels Very small wart-like structures, breaking through the bark of most young twigs. Corky in texture and made of loosely packed cells, providing gaseous exchange between the inner tissues of the stem and the atmosphere.

Lifting A form of transplantation usually involving little root disturbance.

Lignified Woody, hardened.

Ligule A strap shaped organ; a minute projection from the top of the leaf sheath in grasses; the strap shaped corolla in the ray flower of Composites.

Liliflorum/liliflora/liliflorus Epithet meaning flowers like a lily; with big white trumpets.

Limy soil A soil with traces of calcium/lime.

Line A group of plants used for breeding.

Liquid manure A fertilizer made by running water through or into solid manure

Linear Long and narrow.

Lineate Lined; bearing thin parallel lines.

Lined Lightly ridged or ribbed.

Loam A rich soil composed of clay, sand, and organic matter.

Lobed Divided deeply, as applied to leaves.

Lustrous Having a slight metallic gloss, less reflective than glossy.

Lutea/luteum/luteus Epithet meaning yellow, often a lighter shade than aurea (golden).

Macrantha/macranthus/macranthum Epithet meaning larger flowers.

Maculata/maculatum/maculatus Epithet meaning spotted or mottled in color.

Manure Organic matter, excreted by animals, which is used as a soil amendment and fertilizer. Green manures are plant cover crops that are tilled into the soil.

Margin The edge of a leaf.

Maritima/maritimus/maritimum From a seashore or maritime area.

Mature A later phase of plant growth characterized by flowering, fruiting, and a reduced rate of size increase.

Media/soil media Any substrate (organic or not) used to hold plant roots.

Meristem The growing tissue area in a plant; all buds contain a meristem. Areas of actively dividing cells and plant growth; capable of developing into specialized tissues.

Metamorphosis Changing from one state to a different one.

Microclimate Variations of the climate within a given area; a very local or small-scale climate such as valley or woodland.

Micro nutrients Mineral elements which are needed by some plants in very small quantities.

Midrib/midvein The rib or central vein running down the center of a leaf.

Mold A type of fungus that grows on decaying plant tissue.

Mollis A covering of soft hairs.

Moniliform Repeatedly constricted laterally and appearing bead-like.

Monocarpic Fruiting once and then dying.

Monoclonal cultivar A cultivar that correctly represents a single clone.

Monocot A plant of the angiosperm group having one cotyledon.

Monoculture Growing only one particular type of plant.

Monoecious A species with unisexual flowers, having both sexes on the same plant.

Monopodial Continuing growth from a terminal bud each year.

Morifolium Epithet meaning leaves like mulberry, such as mums.

Morphology The study of structure or forms.

Mother block A certified group of plants used to derive propagation tissues.

Mucilaginous Slimy.

Mucronate Ending in a fine, slender tip.

Mulch Any loose material placed over the soil to control weeds and conserve soil moisture. Usually a coarse organic matter, such as leaves, clippings or bark.

Multiple Applied to several buds in or over an axil, instead of the customary single or solitary bud.

Multiple fruit A fruit formed from several flowers included in a single structure having a common axis.

Multi-stemmed Having more than one stem or trunk.

Mummy A dried, shriveled fruit.

Mutation A change in the expected genetic or tissue makeup of a plant. A sudden change in genetic material resulting in an altered individual. Generally disadvantageous to the mutated plant’s survival.

Mycelium/mycelia Thread-like growth parts of many fungi, often white or gray.

Naked Said of a bud which is not covered by scales; the outer pair of leaves serves the same purpose; a flower with no floral envelope (perianth).

Nana/nanus/nanum Epithet meaning dwarf or smaller.

Nascent In the act of being formed.

Native Original to an area.

Native plant Any plant that occurs and grows naturally in a specific region or locality.

Naturalism Planting to create the effect that plants grew in that space without human intervention; gardening to keep or enhance existing natural features.

Naturalized Thoroughly established, but originally from a foreign area.

Nematode mostly microscopic worm-like organisms that damage plant roots

Net veined/netted venation With veins reticulated and resembling a fish net; the interstices close.

Neutral flower A sterile flower consisting of perianth without any essential organs.

Niger/nigrum/nigrus/nigra Dark or blackish in color.

Night-blooming/night-flowering Plants that bloom only in dark or shade.

Nitrate of soda A strong alkaline fertilizer with about 15% nitrogen.

Nitrification The process of oxidizing ammonium salts into nitrogen for plants.

Notched With V-shaped indentations.

Nocturnal Active at night, night-blooming.

Nodal At or pertaining to a node.

Node The point where a leaf or other structure meets a stem node; the part of a stem from which a leaf or new branch starts to grow.

Nodule Round bacteria-filled swellings on the roots of legume plants.

Nomenclature The study of naming plants including spelling and format.

Novae-angliae Epithet meaning from New England.

NPK Nitrogen, Phosphorous and Potash; the three main food elements necessary for plant life. Nitrogen is required for foliage and growth, phosphorous for flowers and potash for roots.

Nut A hard and single-seed fruit found in many trees and shrubs.

Nutrient A chemical required by a plant for growth.

Ob- A prefix meaning inversion.

Obcordate A leaf with rounded lobes at the tip.

Oblique Lop-sided, as one side of a leaf base being larger, wider or more rounded than the other.

Obovate Inversely ovate, broadest above the middle.

Obscure Not easily made out, hidden.

Obtuse With sides forming an angle of more than 90 degrees; having a rounded and blunt apex.

Occidentalis/occidentale Globally western in origin.

Odd pinnate A compound pinnate leaf with a terminal or odd numbered leaflet at the tip.

Oedema Corky portions of leaves caused by excessive humidity.

Offset Small bulb or plantlet used to propagate new plants.

-oides Plant name suffix meaning like or similar to.

Open-pollinated Seeds produced from plants that are allowed to pollinate naturally, primarily through insects, wind and water.

Opposite Said of leaves or leaf scars that are paired on opposite sides at each node.

Orbicular Rounded in two-dimensional outline as many plant leaves

Orbiculate Circular or disc-shaped.

Organic gardening A method of gardening utilizing only materials derived from living or once-alive things.

Organic Something that was or is alive; containing carbon.

Organic material Any material which originated as a living organism.

Ornamental Showy or visually pleasing.

Ornamentals Popular abbreviation for a division of Horticultural Science dealing with plant cultivated for landscape or display value.

Ovary The ovule-bearing part of a pistil; the female part of a flower containing immature seeds (ovules).

Ovate Egg shaped, broadest below the middle.

Ovoid Said of a bud that is egg-shaped, with the broadest portion near the base.

Ovule The egg-containing unit of an ovary, which after fertilization becomes the seed.

Pad and fan cooling The use of a moistened surface and fans to cool a greenhouse.

Pacifica/pacificum/pacificus From near the Pacific ocean or the Western US.

Palmate Radiating, fan-like from a common point; as of leaflets of a palmately compound leaf or veins of a palmately-veined leaf.

Pandurate Fiddle shaped.

Panicle A branched cluster of stalked flowers.

Parasitic plant A plant which lives on, and acquires its nutrients from another plant.

Parterre An ornamental flower garden where beds and paths are arranged to form a pattern. A formal garden construction on a level surface consisting of planting beds, edged in stone or tightly clipped hedging and gravel paths arranged to form a pleasing pattern.

Parvi- Botanical name prefix meaning small or reduced.

Parviflora Having smaller flowers.

Parvifolia Having smaller or shorter leaves.

Pathogen An organism that causes a plant disease.

Peat moss An organic soil additive from Sphagnum and related mosses. The partially decomposed remains of various mosses. This is a good, water retentive addition to the soil, but tends to add the acidity of the soil pH.

Pedate A palmately divided or compound leaf whose two lateral lobes are again cleft or divided.

Pedicel The stalk of a flower or fruit when in a cluster or when solitary.

Peduncle The stalk of a flower cluster or a single flower when the flower is solitary, or the remaining member of a reduced inflorescence.

Pendula/pendulous/pendulum/pendulus Weeping or drooping with branches hanging down from a central stem; a weeping or spreading cultivar.

Perennial A plant that dies down to the ground during winter and survives to grow again each spring;

plants that persist for more than two years.

Perfect flower A flower having both functional stamens and pistils; a plant with both functioning male and female parts.

Pergola An arbor with an open roof of rafters supported by posts or columns; an overhead covering for an outdoor structure. An open framework over a walkway or path, which is usually designed to be covered in climbing plants.

Perianth The two floral envelopes of a flower; a collective term embracing both corolla and calyx as a unit.

Perlite A light weight white-colored soil additive from volcanic materials.

Persicifolia Having leaves shaped like the peach.

Persistent Not deciduous, as applied to leaves; not disappearing, as applied to pith, pubescence, epidermis, etc. Adhering to a position instead of falling, whether dead or alive.

Pest Any insect or animal which is detrimental to the health and well being of plants or other animals.

Petals Modified leaves forming the inner floral envelope.

Petiole Leaf stalk.

Petiolule Leaflet stalk.

pH The scale used to denote the acidity or alkalinity (lime content) of a soil or growing compost. 6.5 pH is considered neutral and supports most plant life.

Phenotype The visual appearance of a plant regardless of genetics.

Photosynthesis The internal process by which a plant turns sunlight into growing energy. The formation of carbohydrates in plants from water and carbon dioxide, by the action of sunlight on the Chlorophyll in the leaves.

Physiology The study of chemical function of any organism.

Phyto- Prefix meaning plant.

Phytogenetics The study of plant genetics and breeding.

Phytopathology The study of plant diseases.

Picta/pictum/pictus Painted; often a variegated or multicolored plant.

Pilose Shaggy with soft hairs.

Pinching back Nipping off the very tip of a branch or stem. Pinching promotes branching, and a bushier, fuller plant

Pistil The seed-bearing organ of a flower, consisting of the ovary, stigma, and style.

Pinked Notched.

Pinna A leaflet of a compound leaf; when applied to ferns, the primary division attached to the main rachis; feather-like.

Pinnate A compound leaf with leaflets or segments along each side of a common axis or rachis; feather-like.

Pinetum Woody plant collection emphasizing conifers.

Pinnata/pinnatum/pinnatus Having pinnate or feather-patterned veins or leaflets. Pinnatio means many small, lateral branches growing off a rib or axis.

Pisifera/pisiferus Literally, pea-bearing.

Pinnule The leaflet of a pinna; a secondary leaflet of a pinnately decompound leaf.

Pistil The female part of a flower composed of ovary, style and stigma.

Pistillate An imperfect flower with a pistil, or seed organ, but having no functional stamens (male pollen producing organs).

Pith The central part of a twig, similar to marrow.

Plicate Folded, as in a folding fan, or approaching this condition.

Plug A small but well-rooted seedling raised in a cellular tray.

Plumose Feather-like, plumy.

Plume Feather-like erect inflorescence.

Pollination Process of transfering pollen from a stamen to a pistil.

Pollinator Cultivar, often a male clone, proven to pollinate other cultivars.

Polyclonal cultivar A cultivar representing two or more distinct clones.

Post-harvest physiology A science relating to fruit and vegetable storage and quality.

Potting soil A growth substrate suitable for container gardening. A soil mixture designed for use in container gardens and potted plants. Potting mixes should be loose, light, and sterile.

Potting Compost Medium for potting plants or for sowing seeds.

Potting on Placing a plant into a larger pot to promote growth etc..

Pod A dry dehiscent fruit; capsule, legume, follide.

Pollen The male cells or microspores produced by the stamens.

Pollination The transfer of pollen from the stamen (male part of the flower) to the pistil (female part of the flower), which results in the formation of a seed. Hybrids are created when the pollen from one kind of plant is used to pollinate and entirely different variety, resulting in a new plant altogether.

Polycarpic Flowering and fruiting many times.

Polygamous Bearing unisexual and bisexual flowers on the same plant.

Pome A type of fleshy fruit represented by the apple, pear or related genera. A fruit with a papery or bony core at the center and with sepals or scars from which the sepals have fallen at the blossom end.

Posterior At or toward the back; opposite the front; nearest the axis; away from the subtending bract.

PPAF Acronym for Plant Patent Applied For.

Precocity Tendency of a given species/cultivar to mature early.

Preformed Already with definite shape or structure, as with leaves within a bud.

Prehensile Clasping, coiling in response to touch.

Pricking out Transplanting small seedlings into larger trays or containers.

Prickles Slender, sharp outgrowths of the stem tissues beneath the epidermis.

Primocane The first year’s shoot or cane of a biennial woody stem.

Procumbens An epithet meaning trailing low along the ground.

Progeny testing the evaluation of seedlings of a particular cross or source.

Propagation Various methods of starting new plants ranging from starting seeds to identical clones created by cuttings or layering.

Provenance The geographic wild origin in terms of site and population.

Propagation Method of increasing the number of plants by dividing roots, layering or start from cuttings.

Procumbent Lying flat on the ground but the stem not rooting at nodes or tip.

Prominent Projecting outward, conspicuous.

Prostrate Lying flat on the ground; a general term.

Protogynous Having the stigma receptive to pollen before the pollen is released from the anthers of the same flower.

Proximal Toward the base, away from the apex.

Pruning Reducing the growth on a shrub/tree to promote new flowers, stems or foliage. Also for cosmetic reasons. The cutting and trimming of plants to remove dead or injured wood, or to control and direct the new growth of a plant.

Ptero- Botanical name prefix meaning winged.

Puberulent Minutely hairy.

Punctate With translucent or covered dots, depressions or pits.

Pungent With a sharp, hard point; sharp and acid to taste or smell.

Purity The relative stability and uniformity of a breeding line.

Quadrangular Four angled, or pith or a twig.

Quick dip Treating cuttings with a liquid hormone.

Raceme A simple indeterminate inflorescence with pedicel led flowers. An elongated , unbranched cluster of stalked flowers.

Rachis The axis along which the leaflets of a pinnate leaf are arranged .

Radial Arranged around and spreading from a common center.

Radical Of or pertaining to the root.

Radicle The embryonic root of a seed.

Ranked Foliage Arranged in longitudinal planes around the stem.

Ray flower A flower with a strap-shaped corolla, usually found on the outer edge of a Compositae inflorescence.

Recurved Bent or curved backward, usually roundly or obtusely so.

Reblooming Typically said of a plant with a spring and later fall blooming

Rebloomer A plant with two or more flowering periods.

Recurrent A plant more or less blooming in two or more sessions or months.

Reflexed Bent abruptly backward or downward.

Relative humidity The measurement of the amount of moisture in the atmosphere.

Reticulate Like a net, the interstices closed. Usually referring to the veins of a leaf.

Registered Said of a cultivar cataloged with an International Registrar (IRA).

Registrar An international authority that catalogues cultivar names (IRA).

Reniformis/reniforme Epithet meaning kidney shaped.

Rhizome An underground stem, capable of storing food, and from which roots and stems of new plants can emerge. An underground stem distinguishable from a root by the presence of nodes, buds or scale-like leaves.

Rib A conspicuous vein of a leaf; or a prominent ridge.

Rhombic With four nearly equal sides, but unequal angles, diamond shaped.

Root anchor A large root that holds a plant in a physical soil mass feeder; a small surface root which easily absorbs nutrients and water.

Root ball The network of roots, with attached soil, of any given plant.

Rootbound A condition which exists when a potted plant has outgrown its container. The roots become entangled and matted together, and the growth of the plant becomes stunted. When repotting, loosen the roots on the outer edges of the root ball, to induce them to once again grow outward.

Rooting Hormone A growth hormone in powder or liquid form, which promotes the formation of roots at the base of a cutting.

Rosea/roseus/roseum Pink.

Rosette A crown of leaves radiating from a stem, and at or close to the surface of the ground.

Rudiment The beginning of an undeveloped plant part.

Rufous Reddish brown.

Rugose Wrinkled, usually covered with wrinkles.

Runner A slender trailing shoot that usually roots at the tip and some nodes; a long offshoot of a plant. A slender stem growing out from the base of some plants, which terminates with a new offset plant. The new plant may be severed from the parent after it has developed sufficient roots.

Samara A dry indehiscent fruit bearing a wing.

Saccate With a sac-like shape.

Saggitate Shaped like an arrowhead.

Sanguinea/sanguineus/sanguineum Bright or blood red.

Sanitation The process of keeping a clean and disease-free growing area.

Saprophyte A plant that lives on decaying organic matter, such as mushrooms.

Scab A fungal scale disease that leaves spots on foliage and fruit.

Scabrous Rough to the touch as with many hairy leaves or stems.

Scald Burning due to strong sun or light

Scale A small and usually dry bract or vestigial leaf or a structure resembling such; a small bract or leaf-like covering of a flower or leaf bud. A small round insect.

Scandent Climbing, usually without tendrils.

Scape A leafless stalk bearing flowers; a leafless peduncle arising from the basal rosette. A scape may be one or many-flowered.

Scarification Deliberate wounding of a seed to allow water to enter

Scion A short length of stem, taken from one plant which is then grafted onto the rootstock of another plant; the top "slip" or desirable propagated tissue in a grafted plant

Scorch Injury to plant parts due to burning by wind or water loss; sometimes used as a synonym of scald, such as burning by the sun.

Scree Rock garden planting bed made of crushed stone and soil.

Screen A tall hedge of many plants used to block wind or a bad view.

Schizocarp A dry dehiscent fruit that splits into two halves.

Scrambler A plant that climbs without twining or grasping in some way.

Scurfy Describes a surface covered with bran-like or flaky particles.

Seascape A landscape planted near the seashore or beach.

Secund One sided.

Seed A fertilized ripened ovule that contains an embryo; a ripened plant ovary capable of germinating to produce another plant.

Seedling A young plant grown from seed.

Seed coat The covering or protective layer around a seed.

Seed Pods The hardened protective shell that contains the maturing seeds of a plant.

Self To cross a plant with its own flowers or one of identical type; said of flowers of one color as opposed to a bicolor.

Self-fertile A plant capable of producing viable seed with its own pollen.

Self-pollination A plant capable of pollinating its own flowers.

Self-sterile A plant not capable of reproducing with its own pollen.

Semi-double A flower with only a few stamens converted to petals; a flower with less than twice the normal number of petals.

Semi-evergreen A plant whose foliage is retained all year in warm climates but not in colder ones; some of the foliage is retained in most climates where hardy.

Semp A common abbreviation for Sempervivum and related genera.

Sempervirens Sepal Modified leaves forming the outer floral envelope.

Serrate Saw-toothed, the teeth pointing forward.

Serrulate Minutely serrate.

Sessile Without a stalk.

Sepal The divided part of a calyx or outer whorl of a flower.

Septum A portion of a fruit.

Setaceous Bristle-like, very narrow; resembling or having a bristle.

Shade A low light planting environment.

Sheath An elongated, more or less tubular structure enveloping an organ or plant part; a tube-shaped part containing a leaf of a grass or similar plant.

Short-season crop A plant capable of producing parts in a minimum of days.

Shrub A woody plant that is usually under 15 feet tall and has many stems.

Shrubby Applied to woody plants which at maturity are less than 20 ft. high, have more than one stem, and no definite crown shape (a purely arbitrary definition); See also "Arborescent".

Sib Shorthand for sibling or sister/brother in a seedling population.

Simple Said of a leaf when not compound, or of an inflorescence when unbranched.

Sinensis/sinense Epithet meaning from China; from Asia generally.

Single flower A flower having only a minimum number of petals for that variety of plant.

Sinuate With a wavy margin.

Sinus The recess between lobes of a leaf or petal; the space between two lobes, segments, or divisions; as of leaves or flower parts.

Slimeflux Exuded mass from a cut or wound woody plant trunk.

Slip A plant cutting.

Sludge Processed sewage, high in nitrogen, which is used as fertilizer.

Smut A fungal disease that often has gray or black spores.

Softwood cutting A herbaceous (often green) cutting of young stems.

Soil drench A media treatment to kill fungi.

Soilless mix A substrate for plant roots with manmade materials.

Soil pH The measure of the amount of lime (calcium) contained in soil.

Solitary Single, one.

Sooty mold A fungus that develops on insect secretions.

Spaghetti irrigation/spaghetti tube The popular name for drip irrigation because of long narrow tubes used.

Sphagnum Dried bog moss. Most peat moss is composed primarily of sphagnum moss. This moss is also packaged and sold in a fresh state, and used for lining hanging baskets and air layering.

Spathe A large hood-like bract enclosing flowers.

Spatulate Spoon shaped.

Speciation the evolutionary process of a wild population becoming a new distinct species.

Species A natural group of plants composed of similar individuals which can produce similar offspring, usually including several minor variations; a unit of botanical classification capable of reproducing itself.

Spicate With spikes; having the shape or form of a spike.

Spike A usually unbranched, elongated, simple, indeterminate inflorescence whose flowers are sessile; an unbranched stalk full of flowers.

Spine A modified very sharp leaf, similar to thorn and prickle; sharp outgrowths of the twig, sometimes but not always paired at the nodes.

Spinosa Epithet meaning with spines, prickles or thorns.

Spinose/spinosissima With many spines.

Spittle bug Frog hoppers that suck sap from plant stems and produce saliva.

Spongy Irregularly interrupted by small, sometimes scarcely distinguishable cavities; porous.

Spore A minute reproductive body comprised of a single gametophytic cell; a simple reproductive cell of ferns, mosses or fungi.

Sporocarp A body containing sporangia or spores.

Sporophyll A spore bearing leaf.

Sport A shoot that differs from a plant and can be reproduced as such.

Spreading Growing outward or horizontally.

Spur shoots Short stubby branches with greatly crowded leaf scars and very slow growth, often bearing flower buds.

Spreader A mechanical device to spray chemicals; a chemical used to disperse pesticides uniformly over a plant surface.

Spur A projection of a flower; a short thick stem that produces flowers and fruit.

Stake A piece of wood/plastic/metal used to support stems or flowers.

Stalk A supporting structure of a leaf, flower or fruit.

Stalked Said of buds with scales elongated perceptibly below the lowest scales.

Stamen The male part of a flower composed of the anther and filament; the pollen bearing male part of a flower; organ of a seed plant.

Staminate An imperfect flower with stamens or pollen producing structures, but with no pistil, or seed producing structure.

Staminate Having or pertaining to a stamen or pollen-bearing part of a flower.

Standard A small tree commonly produced by grafting a weeping or dwarf form on a trunk of the desired height. An upright single-stemmed plant as grafted tree roses; an upright petal as in many members of the pea family.

Starch A stored carbohydrate in plant parts.

Stellate Star-shaped as in radiating petals or minute plant hairs.

Stem The trunk and its branches; one of the three fundamental parts of a higher plants- root, stem and leaf. A vascular growing axis of a plant with buds and growing nodes.

Sterile Lacking fertility or reproductive potential; said of a soil heated or treated to remove harmful organisms. Barren, not able to produce seed.

Sterilization The process of killing insects and disease in soil; process of killing harmful organisms on cultured plant tissue.

Stick Verb used when one places cuttings in a rooting medium or bed.

Stigma The receptive female portion, usually the distal end of a pistil, of a flower that receives pollen.

Stipe The stalk of a fern frond or stalk of a flower pistil.

Stipel A stipule of a leaflet.

Stipellate Having stipules at the base of the leaflets.

Stipular Having stipules at the base of the leaves.

Stipules Small leaf-like organs occurring in pairs on either side of the leaves; occasionally each one extends half way around the twig, respectively.

Stipule scars A pair of marks left after the stipules fall off, to either side of the leaf scar.

Stock The basal or rooted part of a grafted plant; a group of preserved nursery plants used for propagation.

Stolon A slender horizontal stem which produces new plants; a horizontal stem that roots at its tip and grows a new plant.

Stoloniferous Producing stolons.

Stomata A minute pore in the epidermis, especially in the lower surface on the leaf. The breathing pores of a leaf.

Stomate A breathing or water pore of a plant leaf or stem; sweat gland.

Stool A clump of roots used for propagation, usually applied to layering

Strain A race within a species reproduced by seed; many are now cultivars.

Stratification A temperature treatment of seed used to break dormancy.

Stratified Arranged in horizontal layers.

Striate Striped or having long lines, channels or ridges.

Strike To produce roots, as with a cutting.

Strobilus A term for a conifer cone.

Style The long female stalk or pistil between the stigma and ovary.

Sub- A prefix meaning nearly or almost.

Subcontinuous pith With occasional but not regular gaps in the pith.

Suberization A formation of corky bark on wounded cuttings or stems.

Submerged bud A bud hidden by the petiole or embedded in the callus of the leaf scar.

Subopposite Said of paired leaf scars that are close, but not at exactly the same height on the twig (staggered).

Subshrub A partly woody plant.

Subtending Standing below.

Succulent A fleshy plant that hold water in itself, usually in the leaves or stem. Thickened, juicy, fleshy tissues that are more or less soft in texture.

Sucker A vigorous shoot arising from a plant base or from below ground; also the adhering discs of a vine. A growth originating from the rootstock of a grafted plant

Suffrutescent A plant with stems that are woody at the base, usually dying back to the woody stems or even back to the ground after severe winters. Half- or sub-shrub.

Suffruticose Shrubby; densely bushy plants.

Summer annual A one year plant that sows in spring and flowers in summer or fall.

Sunscald A burning of tissue due to strong light on foliage or bark.

Superficial On the surface, not connected to inner tissues.

Supine Lying flat, face upwards.

Suture A line of dehiscence or groove marking a face of union.

Superposed Said of extra buds that appear above the true axillary buds; usually flower buds.

Sylvestris/sylvestre Epithet meaning of the woods.

Syncarp A rounded aggregation of fruits; a fleshy aggregate fruit.

Systemic pesticide/systemic herbicide A chemical that is absorbed by a plant and is translocated in its vessels, either to kill feeding insects on the plant, or to kill the plant itself.

Tap root The primary or thick main root growing straight down from a plant.

Taxonomythe The science of plant classification and nomenclature.

T-budding A type of grafting that places a bud into a T-shaped cut on a stock.

Temperate zone Northern hemisphere of the world.

Tender plants Plants that are unable to endure frost or freezing temperatures.

Tendril The twisting, clinging, slender growth on many vines, which allows the plant to attach themselves to a support or trellis; a twisting thread-like shoot used to support the plant. A climbing organ metamorphosed from a leaf, stipule or stem.

Tepal A segment of perianth not differentiated into calyx or corolla.

Terminal The end bud beyond which no further growth takes place normally until the following season. At the tip or distal end.

Ternate In threes.

Terrarium A glass or plastic-enclosed growing environment with high humidity

Texture The relative coarseness or fineness of foliage in the landscape

Thallus A flat leaf-shaped part in the early life cycle of a fern

Thatch The layer of dead stems that builds up under many lawn grasses.

Throat The inner mouth-like opening of a tubular flower.

Thinning Removing excess seedlings, to allow sufficient room for growth and better size and quality in the remaining plants. Removing stems or branches, to give the plant a more open structure.

Thorns Sharp outgrowths of the twig that represent modified branches; usually bearing leaf scars, or branched.

Tomentose With a wooly covering of short hairs.

Tomentulose Microscopically tomentose or woolly.

Tomentum Densely matted hairs.

Toothed A margin that is broken up into small rather regular segments.

Torsion Twisting.

Torulose Twisted or knobby, irregularly swollen at close intervals.

Top-dressing A fertilizer or compost applied at the soil level.

Top working Grafting only the ends of a plant, leaving branches intact.

Topiary The art of pruning and training plants into specific shapes.

Topsoil The top layer of native soil. This term may also apply to good quality soil sold at nurseries and garden centers.

Trailing Prostrate, running down or along the ground, or not rooting.

Translocation The movement of water and nutrients through a plant’s vessels.

Transpiration The release of moisture through the leaves of a plant.

Transplant A seedling that grows its first true leaves, which resemble the adult plant leaves rather than the seed leaves that first appear.

Transplanting The process of digging up a plant and moving it to another location.

Transplantation The process of moving a plant from one soil mass to another.

Transverse ridge A ridge that runs across the stem from one leaf scar to its pair on the opposite side of the twig.

Trench layering A method of propagation using long branches rooted in a manmade ditch.

Trenching Digging a shallow ditch around the border of a planting.

Trichomes Bristle or hairs.

Tricolored A plant with three colors.

Trifoliate Three-leaved.

Trifoiolate A leaf with three leaflets.

Triloba/trilobus/trilobum Epithet meaning three major lobes in the leaf or other part.

Triploid With three sets of chromosomes; many of these plants are seedless.

True Leaves The first hardy leaves, usually the second pair, on a new plant.

Truncate With a leaf or part abruptly cut.

Truss A non-technical term for a domed flower mass.

Tuber A flat underground stem that stores food and plant energy, with growing points from which a plant grows.

Tubercle A miniature tuber, tuber-like structure or projection.

Tuberous With tubers or part resembling them.

Turf A dense mat of lawn grasses cut very low.

Tumid Swollen.

Tunicated With concentric layers, often of fleshy scales.

Turgid A plant part that is swollen and full of water.

Twiggy Having many divergent twigs.

Twining A stem winding around a support.

Type Identifies each plant according to various accepted groupings such as shrub, perennial or grass. A pressed herbarium specimen.

Umbel Usually a flat-topped flower cluster, with pedicels and peduncles arising from a common point, resembling the supports of an umbrella.

Unarmed Without either spines or prickles, though the leaves may have sharp teeth at the margins or tip like holly.

Uncinate Hooked at the tip.

Undulate Wavy, as a leaf margin.

Unisexual flowers Flowers having either pistils or anthers, but not both.

Unisexual Withonly one sex (male or female) of flowers on a single plant.

Urban horticulture The study of stresses affecting city trees, gardens and landscapes.

USDA United States Department of Agriculture.

USNA United States National Arboretum.

Vein The rib or branch of vessels in a plant leaf or other flat part.

Valvate Applied to bud scales that meet along a definite, usually longitudinal, line without overlapping; the reverse of imbricate.

Variant A variation between strains; a plant that is genetically different from the wild plant.

Variedad Spanish word for variety; a true cultivar.

Variegate A cultivar with variegated parts.

Variegated Striped, margined or mottled with colors other than green, where green is normal; having markings or zones of tissue lacking green chlorophyll.

Variety One of possibly many closely-related plant species. A naturally occurring variation of a wild species.

Variety Subdivision of a species having a distinct though often inconspicuous difference, and breeding true to that difference. Also refers to clones.

Vascular The vessels that conduct water or nutrients in plants.

Vascular bundle A discrete group of conducting vessels.

Vascular bundle scar A minute spot within the leaf scar where the vessels were positioned.

Vegetative The leafy or green portions of a plant.

Venation Arrangement or pattern of veins or vessels and their relative association.

Venulose With very fine hairs.

Verdant Characterized by abundance of verdure, green in tint or color.

Verdure Lush greenness of flourishing vegetation.

Vermiculite The mineral mica, heated to the point of expansion. A good addition to container potting mixes, vermiculite retains moisture and air within the soil.

Vernacular name A name in a common local language.

Vernal Related to spring.

Vernation The arrangement of leaves within a bud.

Verrucose Having a wart-like surface.

Verticillate Arranged in whorls or arranged in a radiating patterns.

Vesicle A small bladdery sac or cavity filled with air or fluid.

Vestige The remains of an exhausted or dead plant structure.

Viable/viability Seed or spores capable of germination with suitable treatment.

Villous Having long, soft, shaggy hairs that are not matted.

Vine A slender stemmed plant that trails and climbs by means of attaching parts and stems.

Virescent Becoming green.

Virginiana/virginianum/virginianus From the Southeastern USA.

Virus A deforming microorganism that causes disease and death.

Vivipary/viviparous With live plantlets on a mother plant.

Virus indexing A procedure to test plant stock to determine if it has a virus.

Viscid Sticky or with appreciable viscosity.

Voluable Readily flowing, twining.

Wall garden A garden against a man-made structure to protect plants.

Wardian case/Wardian An ornate 19th century terrarium used for ferns and rare plants.

Waterlogged Said of soil that is oversaturated with water.

Water sprout A vigorous sucker from the base of a woody plant.

Whip A long scion used for tongue and groove grafting.

Whorled Arranged around a central point; leaves not alternate nor opposite.

Wildlife garden Planting with plants to attract, feed and house wild animals, insects and birds.

Willow water A solution of willow bark that aids in rooting cuttings.

Winter annual A one year plant that sows in fall/winter and flowers early spring.

Woody plant A tree or shrub; any plant with lignified tissues.

Wounding Deliberately cutting plant stems to increase root formation.

Weeping Dropping conspicuously, pendant.

Whorled An arrangement of three or more structures arising from a single node.

Woolly Having long, soft, more or less matted or tangled hairs; like wool.

X Indicates a hybrid.

Xeriphyte A plant naturally adapted to drought or low moisture conditions.

Xeriscape A landscape made of plants that require very little water or rain.

Zone An area distinguished by a range of annual average minimum temperatures, used in describing plant hardiness. Regions that share similar climatic and rainfall conditions producing similar growing seasons.