Abortive. Defective or barren, through non-development of a part.

Acuminate. Long-pointed.

Acute. Ending with a sharp but not prolonged point.

Adherent. Growing fast to; adnate anther, attached for its whole length to the ovary.

Adnate. Essentially same as adherent, with the added idea of congenital adhesion.

Aggregate fruit. A fruit that develops from the fusion of more than one carpel within a single flower. (examples: raspberry, blackberry)

Ament. A usually dense, cylindrical, often drooping cluster of unisexual apetalous flowers found in willows, birches, and oaks. Also called catkin.

Anther. The part of the stamen which bears the pollen.

Appressed. Lying close against another organ.

Ascending. Rising upward, or obliquely upward.

Axil. The junction between a stem and a leaf.

Bract. Reduced leaf subtending a flower or flower-cluster.

Branches, primary. The leading or main branches thrown out directly from the trunk, giving a general shape to the plant.

Branches, secondary. Never directly from the trunk but from other branches.

Buttressed. Supported against strain in any direction by a conspicuous ridge-like enlargement of the trunk vertically to the roots. Several of these buttresses often give a tree a square appearance.

Caducous. Dropping off very early after development.

Calyx. The outer set of the leaves of the flower.

Campanulate. Bell-shaped.

Capitate. Forming a head like mass or dense cluster, as the flowers of plants in the composite family.

Capsule. A dry dehiscent fruit that develops from two or more united carpels.

Carpel. A simple pistil.

Catkin. A usually dense, cylindrical, often drooping cluster of unisexual apetalous flowers found in willows, birches, and oaks. Also calledĀ ament.

Ciliate. Margin with hairs or bristles.

Coherent. One organ uniting with another.

Compound. See leaf, ovary, etc.

Connate. Similar organs, more or less grown together.

Connective. The part of the anther connecting its two cells.

Coriaceous. Thick, leathery in texture.

Corolla. Leaves of the flower within the calyx.

Corymb. A corymb is similar to a panicle with the same branching structure, but with the lower flowers having longer stems, thus creating a flatter top.

Crenate. Edge with rounded teeth.

Crenulate. Edge with small rounded teeth.

Cyme. Flat-topped or convex flower-cluster, the central flower opening first; blossoming outward.

Deciduous. Falling off, as leaves in autumn, or calyx and corolla before fruit grows.

Declining. Bent downwards.

Decurrent. Leaves prolonged on the stem beneath the insertion: branchlets springing out beneath the point of furcation, as the feathering along the trunk of elms, etc.

Dentate. Edged with toothlike projections; toothed: dentate leaves.

Disk. Central part of a head of flowers; fleshy expansion of the receptacle of a flower; any rounded, flat surface.

Drupe. A stone fruit; soft externally with a stone at the center, as the cherry and peach.

Erose. Eroded, as if gnawed.

Exserted. Protruding, projecting out of.

Falcate. Scythe-shaped.

Fertile. Capable of producing fruit; or productive, as a flower having a pistil or an anther having pollen.

Fibrovascular. Bundle or tissue, formed of wood fibers, ducts, etc.

Filament. Part of stamen supporting anther.

Fungus. A division of cryptogamous plants, including mushrooms, etc.

Furcation. Branching.

Glabrous. Smooth without hairiness or roughness.

Glandular. Bearing glands or appendages having the appearance of glands.

Glaucous. Covered with a bloom: bluish hoary.

Globose or globous. Spherical or nearly so.

Habit. The general appearance of a plant.

Habitat. The place where a plant naturally grows, as in swamps, in water, upon dry hillsides, etc.

Hybrid. A cross between two species.

Imbricated. Overlapping.

Inflorescence. A cluster of flowers arranged in a particular way on a stem. Spikes, racemes, umbels, whorls, panicles, cymes, and corymbs are common types of inflorescences.

Involucre. Bracts subtending a flower or a cluster of flowers.

Keeled. Having a central dorsal ridge like the keel of a boat.

Key. A winged fruit; a samara.

Lacerate. Irregularly cleft, as if torn.

Lanceolate. Lance-shaped, broadest above the base, gradually narrowing to the apex.

Leaf. Consisting when botanically complete of a blade, usually flat, a footstalk and two appendages at base of the footstalk; often consisting of blade only.

Leaf, compound. Having two to many distinct blades on a common leafstalk or rachis. These blades may be sessile or have leafstalks of their own.

Leaf, pinnately compound. Pinnately compound leaves have the leaflets arranged along the main or mid-vein.

Leaf, palmately compound. With leaflets all standing on summit of petiole.

Leaf-cushions. Organs resembling persistent decurrent footstalks, upon which leaves of spruces, etc., stand; sterigmata.

Leaf-scar. The mark left on the twig at the point of attachment of a leaf petiole when the leaf falls.

Lenticel. Raised pore on the surface of bark, which provides access for air to the inner tissues.

Linear. Long and narrow with sides nearly parallel.

Monopetalous. Having petals more or less united.

Mucronate. Abruptly tipped with a small, sharp point.

Nerved. Having prominent unbranched ribs or veins.

Obcordate. Inversely heart-shaped.

Obovate. Ovate with the broader end towards the apex.

Obtuse. Blunt or rounded at the end.

Orbicular. Having a circular or nearly circular outline.

Ovary. The part of the pistil containing the ovules.

Ovoid. A solid with an oval or ovate outline.

Ovuliferous. Bearing ovules.

Panicle. General term for any loose and irregular flower-cluster, commonly of the racemose type, with pedicellate flowers.

Pedicel. The stalk of a single flower in the ultimate divisions of an inflorescence.

Peduncle. The stem of a solitary flower or of a cluster.

Perfect. Having both pistils and stamens.

Perianth. The floral envelope consisting of calyx, corolla, or both.

Persistent. Not falling for a long time.

Petal. A division of the corolla.

Petiole. The stalk of a leaf, attaching the blade to the stem.

Petiolule. The stalk of a leaflet in a compound leaf.

Pistil. Female reproductive structure of a flower, composed of an ovule-containing ovary at the base, one or more pollen-receiving stigmas at the tip.

Pistillate. Provided with pistils; usually applied to flowers without stamens.

Pollen. The fertilizing grains contained in the anthers.

Puberulent. Minutely pubescent.

Pubescent. Covered with short soft or downy hairs.

Raceme. A simple cluster of pediceled flowers upon a common axis.

Rachis. The main axis of a compound leaf, of a raceme or of a spike.

Ramification. Branching.

Range. The geographical extent and limits of a species.

Reflexed. Turned backward.

Reticulated. Netted; in the form of a network.

Revolute. Rolled backward from the margin or apex.

Samara. Key fruit; winged fruit, like that of the ash or maple.

Scarf-bark. The thin, outermost layer which often peels off.

Segment. One of the divisions into which a plane organ, such as a leaf, may be divided.

Sepal. A calyx leaf.

Serrate. With teeth inclining forward.

Serrulate. With small teeth inclining forward.

Sessile. Not stalked, as when the leaf blade or flower rests directly upon the twig.

Simple leaf. Not compound, having one blade not jointed with its stem.

Sinuate. Strongly wavy-margined.

Sinus. Interval between two lobes or divisions of a leaf; sometimes sharp-angular, sometimes rounded.

Spatulate. Gradually narrowed downward from a rounded summit.

Spike. A cluster of sessile or nearly sessile lateral flowers on an elongated axis.

Spray. The smaller branches and ultimate branchlets of a tree taken as a whole.

Stamen. The pollen-bearing organ of a flower, each stamen consisting of a filament (stem) and anther which contains the pollen.

Staminate. Having stamens.

Sterile. Variously applied: to flowers with stamens only; to stamens without anthers; to anthers without pollen; to ovaries not producing seed, etc.

Stigma. Part of pistil which receives the pollen.

Stipels. Appendages to a leaflet, analogous to the stipules of a leaf.

Stipules. Appendages of a leaf, usually at the point of insertion.

Striate. Streaked, or very finely ridged lengthwise.

Style. Part of pistil uniting ovary with stigma; often wanting.

Sucker. A shoot of subterranean origin.

Suture. The line of union between parts which have grown together; most often used with reference to the line along which an ovary opens.

Terete. Cylindrical.

Ternate. In threes.

Tomentose. Covered with short, dense, matted hairs.

Truncate. As if cut off at the end.

Umbel. An inflorescence in which the flower stems spring from the same point like the rays of an umbrella.

Verticillate. Arranged in a circle round an axis; whorled.

Villose or villous. With long, soft hairs.

Whorl. Arranged in a circle about an axis.