Glossary Of Botanical Terms

The technical terms of botany are often difficult and obscure, but they represent an indispensable, precise shorthand when describing the physical attributes of plants. Without them, many more words would be needed to ensure a complete and accurate description. The following glossary covers the technical terms used in this site, as well as some others commonly encountered in books about plants.

Achene-a small, dry fruit that contains one loose seed and that does not split open spontaneously (e.g., sunflower "seed")

Acuminate-tapering gradually to a point at the apex

Acute-coming sharply to a point at the apex

Alternate-arranged singly at different points along a stem or axis

Annual-completing the cycle from seed to death in one year or season

Apex-the tip

Appressed-pressed flat or close up against something

Aril-an outer covering or appendage of some seeds

Ascending-rising upward gradually from a prostrate base

Awn-a bristle characteristic of the spikelets in some grasses

Axil-the angle formed by a stem h a branch, leaf stalk, or flower stalk growing from it

Axillary-growing from an axil

Axis-the main stem of a plant, or a central line of symmetry, development, or growth

Berry-a stoneless, pulpy fruit containing one or more embedded seeds (e.g., grape)

Biennial-completing the cycle from seed to death in two years or seasons

Bilabiate-two-lipped

Bipinnate-pinnate, with pinnate leaflets

Blade-the broad, thin part of a leaf or petal

Bloom-a powdery, whitish coating on leaves, stems, or fruit

Bract-a small, sometimes scale-like leaf, usually associated with flower clusters

Bud-a protuberance on a stem, from which a flower, leaf, or shoot develops

Bulb-a thick, rounded, underground organ consisting of layered, fleshy leaves and membranes

Calyx-the outer part of a flower, usually consisting of green, leafy sepals

Capsule-a dry, many-seeded, spontaneously splitting fruit that arises from a compound pistil

Carpel-the wall of a simple pistil, or part of the wall of a compound pistil

Catkin-a spikelike flower cluster that bears scaly bracts and petalless, unisexual flowers

Cauline-relating to or growing on a stem

Clasping-partly or completely surrounding the stem

Claw-the narrow, curved base of a petal or sepal in some flowers

Compound-made up of two or more definable parts

Compound pistil-a pistil made up of two or more partially or completely united carpels

Cone - a rounded, more or less elongated cluster of fruits or flowers covered with scales or bracts

Cordate-heart-shaped, with the point at the apex

Corm-a bulblike but solid, fleshy underground stem base

Corolla-the petals of a flower, which may be separate or joined in varying degrees

Corymb-a generally flat-topped flower cluster with pedicels varying in length, the outer flowers opening first

Creeper-a shoot that grows along the ground, rooting all along its length

Crenate-having rounded teeth along the margin

Culm-the hollow stem of grasses and bamboos

Cyme-a branching, relatively flat-topped flower cluster whose central or terminal flower opens first, forcing development of further flowers from lateral buds

Deciduous-falling off each season (as leaves); bearing deciduous parts (as trees)

Decompound-having divisions that are also compound

Decumbent-lying on the ground but having an ascending tip

Decurrent-descriptive of leaves whose edges run down onto the stem

Dentate-sharply toothed, with the teeth pointing straight out from the margin

Digitate-compound, with the elements growing from a single point

Dilated-expanded, broadened, flaring

Disk flower-one of the tubular flowers or florets in the center of the flower head of a composite flower such as the daisy (see also ray flower)

Dissected--cut into fine segments

Double-descriptive of flowers that have more petals than normal

Doubly serrate-serrate, with small teeth on the margins of the larger ones

Drupe-a fleshy fruit containing a single seed in a hard "stone" (e.g., peach)

Entire-having no teeth or indentations Evergreen-retaining green foliage for more than one season

Filiform-threadlike

Floret-a small flower in a flower head or other cluster

Frond-the leaf of a fern

Fruit-the seed-bearing part of a plant

Funnel form-descriptive of a flower whose corolla tube widens gradually and uniformly from the base

Glabrous-not hairy

Glandular-having glands, which secrete sticky substances

Glaucous-covered with bloom

Globose-approximately spherical

Grain-achene-like fruit, but with the seed not loose

Head-a flower spike or raceme shortened to form a compact, flattened to globose cluster

Herb--a plant that has no woody tissue and that dies down to the ground at the end of a growing season

Herbaceous-herblike; not woody

Hesperidium-a partitioned berry with a leathery, removable rind (e.g., orange)

Hoary-closely covered with short and fine whitish hairs

Incised-sharply and irregularly slashed or cut

Indigenous-native; naturally occurring

Inflorescence-technically, the way flowers are arranged in a cluster; generally, a flower cluster

Internode-the part of a stem or branch between nodes

Interrupted-descriptive of a structure, the pattern or sequence of whose elements is broken by the insertion of other elements

Lanceolate-widening to a maximum near the base and tapering to a point at the apex

Lateral-occurring on or growing from the side (compare terminal)

Leaf-a vegetative organ which, when complete, consists of a flat blade, a petiole or stalk, and (usually two) small leafy appendages at the base of the petiole

Leaflet-a division or part of a compound leaf

Legume-a one-celled fruit that splits along two sutures or seams (e.g., pea)

Linear-long and narrow, with nearly parallel sides

Lip-one of the parts in a corolla or calyx divided into two unequal parts

Lobe-a part or division, especially when rounded, of an organ

Lyrate-lobed to resemble a lyre, with the terminal lobe largest and the lower lobes smaller

Node-the place where a leaf grows or can grow

Nut-a hard-walled, one-seeded fruit that does not split spontaneously (e.g., hazelnut)

Ob -a prefix that indicates reversal of the usual orientation (e.g., oblanceolate means widening gradually from the pointed base to-a maximum near the apex, which may be more or less rounded) `long-longer than wide and rounded at the ends, with nearly parallel sides for much of the length

Obtuse-rounded or blunt

Opposite--growing two to a node on opposite sides

Orbicular-circular or approximately round

Oval-broadly elliptical

Ovate-shaped like an egg, with the narrow end at the apex

Ovoid-ovate

Palmate-compounded, divided, lobed, or ribbed so that the divisions or ribs spread out like fingers from a single point

Panicle-a raceme compounded by branching

Papilionaceous-descriptive of a flower whose petals are arranged to resemble a butterfly

Pedicel-the stalk of one flower in a cluster

Peduncle-the stalk of a flower cluster or of a solitary flower

Peltate-having a stalk attached at or near the middle Perennial-living through three or more seasons

Persistent-remaining on the plant; not falling off readily Petal-one unit of the corolla

Petiole-the stalk of a leaf

Pinna (plural pinnae)-a leaflet or primary division of a pinnately compound leaf

Pinnate-having leaflets arranged in oftosite rows along the petiole

Pinnatiful-split about halfway to the midrib, such that the divisions are pinnately arranged

Pinnule--one of the divisions of a pinnate leaflet in a bipinnate leaf

Pistil---the female reproduction organ of a flower

Pod-generally, a dry fruit that splits open

Pome-a fleshy fruit with a central seed-bearing core (e.g., apple)

Procumbent-growing along the ground without rooting, and having ascending tins

Prostrate-growing flat along the ground

Pubescent-covered with down or soft, short hairs

Punctate-having translucent spots or depressions

Raceme-an elongated flower cluster in which flowers grow on pedicels along part of the length of the peduncle

Radical-growing from or pertaining to a root; growing from a non-aerial stem

Ray flower--one of the flattened, petal-like outer flowers or florets ringing the disk in the heads of some composite flowers, such as the daisy (see also disk flower)

Receptacle-the end of the stem or stalk on which the flower parts are borne

Rhizome-an underground portion of a stem, producing shoots on top and roots beneath; different from a root in that it has buds, nodes, and scaly leaves; rootstock

Rootstock-rhizome

Rosette-a circular or spiral arrangement of leaves growing from a center or crown

Runner-a thin stem or shoot growing along the ground and producing roots at the nodes

Sagittate-resembling an arrowhead in shape

Samara -a winged fruit that does not split spontaneously (e.g., maple)

Scale-a small, usually dry leaf that is closely pressed against another organ

Scape-a leafless flower stalk that grows from the ground

Sepal-a leaf or division of the calyx

Serrate-saw-toothed, with the teeth pointing toward the apex

Sessile-having no stalk

Sheath-an expanded or tubular structure that partially encloses a stem or other organ

Shoot-a stem or branch and its leaves, especially when young

Shrub-a woody plant that produces no trunk but branches from the base

Simple-not compounded (leaves) or branched (stems, flower clusters)

Smooth-not rough (compare glabrous)

Solitary-not growing as part of a cluster or group

Spadix-a fleshy spike

Spathe-one or two bracts enclosing a flower cluster (especially a spadix)

Spatulate-shaped like a spoon, with a narrow end at the base

Spike-a flower cluster in which sessile flowers grow along part of the length of the peduncle

Spikelet-a small spike, particularly one of the few flowered spikes making up the inflorescence of a grass

Spore-a one-celled reproductive body produced by relatively primitive plants

Spur-a slender, hollow projection from a petal or sepal

Stamen-the male or pollen-bearing organ of a flower

Strobile-a cone or conelike structure

Style-the slender, elongated part of a pistil

Suture-a natural seam or groove along which a fruit splits

Taproot-a single main root that grows vertically into the ground

Terminal-occurring at or growing from the end opposite the base (compare lateral)

Ternate--occurring in threes or divided into three parts

Trifoliate-having three leaves,

Trifoliolate-having three leaflets

Tripinnate-descriptive of a pinnate leaf having pinnate -leaflets with pinnate pinnules

Tuber-a thick, fleshy part, usually of a rootstock

Umbel-a more or less flat-topped flower cluster in which the pedicels (rays) arise from a common point. In compound umbels, each primary ray terminates in a secondary umbel

Valve-one of the parts into which a capsule divides when splitting

Whorl-a circular arrangement of three or more leaves, flowers, or other parts at the same point or level