The object of these pages is to give as briefly as possible a simple explanation of those botanical terms most frequently used in describing plants.
Rootstock: a creeping stem growing below the surface of the ground. Tuber: a thick portion of a rootstock, usually possessing eyes like a potato. Corm: the thick fleshy base of a stem. Bulb: an underground stem covered with scales. Stolon: a basal branch, rooting at the nodes.
Erect: upright. Simple: not branched.
Decumbent: horizontal on the ground, but vertical at the end. Procumbent: flat on the ground.
Creeping: running along the earth and rooting at the joints. Scape: the leafless flower-stalk of a stemless plant.
Node: the junction of two portions of the stem, often hard and swollen, at which leaves are usually borne.
Bract: a leaf subtending a flower.
Involucre: a circle of bracts round a flower, as in the Sunflower.
Entire: one the edge of which is not cut or lobed.
Simple: one which is not divided into leaflets.
Compound: one which is divided into leaflets.
Alternate: when one leaf grows just above the other on another side of the stem. Opposite: when two appear at each joint, having the semicircle of the stem between them. Whorled: when they grow in a circle round the stem. Cordate: heart-shaped. Obcordate; inversely heart-shaped.
Linear: very narrow, like grass.
Lanceolate: narrow, tapering towards the top.
Oblanceolate: inversely lanceolate.
Ovate: egg-shaped, broader at the bottom.
Obovate: egg-shaped, broader at the top.
Elliptical: oblong, narrowed at the top and bottom.
Oval: broadly elliptical.
Spatulate: rounded at the top and narrow at the base.
Reniform: nearly round, with a deep indentation at the stalk.
Auriculate: having two rounded lobes at the base.
Sagittate: having two pointed lobes at the base.
Undulate: with wavy margins.
Crenate: with rounded teeth on margins.
Serrate: with sharp teeth on margins.
Incised: with deep jagged teeth.
Lobed: with divisions cut to about the middle.
Cleft: with divisions cut more than halfway into the leaf.
Divided: cleft to the midrib.
Pubescent: covered with fine hairs.
Glabrous: without any hairs, smooth.
Glaucous: covered with a bloom, as on the plum.
Mucronate: with a short sharp tip.
Calyx: the outer lower set of leaves at the base of the flower. Usually green, but sometimes bright coloured.
Sepals: the leaves of the calyx when it is divided to the base.
Corolla: the inner set of leaves of the flower.
Petals: the leaves of the corolla when it is divided to the base.
Perianth: said of a flower having only one set of floral leaves.
Pedicel: the small individual stalk of a flower borne in a cluster.
Peduncle: the main flower-stalk.
Sessile: said of flowers that grow close to the stem and have no pedicels.
Raceme: a long-shaped flower-head formed by numerous flowers growing on pedicles along the sides of a common stalk.
Spike: a raceme with sessile flowers.
Head: a dense spike, globular in shape, like a Clover.
Corymb: a raceme with the lower flowers on longer stalks, so that the cluster is almost flat on the top, as in the Yarrow.
Umbel: like a corymb, but with the pedicels all branching from a central point.
Axillary: growing from the axil or angle, formed by the leaf and the stem. Stamens: composed of Filament: the stalk to uphold the anther. Anther: a tiny box containing the pollen. Pollen: the fertilizing powder of the plant. Pistil: composed of
Ovary: containing the ovules, or undeveloped seeds. Style: a slender stalk surmounting the ovary.
Stigma: a variously formed tip of the style, which has a rough moist surface to catch the pollen that fertilizes the seeds by means of minute tubes that penetrate the style and convey the pollen from the stigma to the ovules. Spadix: a fleshy spike, as in the Arum Lily. Spathe: the concave bract enveloping a spike.
Achene: a dry one-seeded fruit.
Berry: a pulpy fruit.
Capsule: a dry fruit with two or more carpels.
Drupe: a single fruit, with a fleshy outer wall and a bony inner wall.
Plumose: resembling a plume, like the Clematis in seed.
Sterile: without seed.