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