Achene

a hard, dry, indehiscent, one-celled, one-seeded fruit; e.g. Buttercup.

Acicular

needle-shaped, tapered.

Acuminate

coming: to a point, which is elongate, with concave sides.

Acute

coming to a sharp point, not prolonged.

Adnate

attached by the whole base or side.

Adpressed

closely touching.

Aestivation

the manner of arrangement or folding of parts in the bud of a flower.

Aggregate

of fruits, closely arranged or contiguous carpels.

Alae

wings of the corolla in Leguminosae (posterior lateral petals).

Alternate

not opposite, as in leaves, etc.

Amphibious

addicted to land or water conditions.

Amplexicaul

half-clasping the stem, as the bases of leaves.

Anemochorous

dispersed by wind.

Anemophilous

pollinated by the wind.

Annual

of one year's duration.

Anterior

situated in the forepart.

Anther

the distal part of the stamen which contains the pollen.

Anthocyanin

purple colouring-matter in cells.

Apex

the part most removed from the base or attachment.

Apiculate

with a small apical point, as the tip of the midrib in some cases.

Apocarpous

when the carpels are not united.

Aquatic

growing in water, submerged or with leaves floating.

Arcuate

forming an arch or bow.

Arenophilous

growing on sand.

Ascending

growing upwards, and approaching a vertical position.

Asperous

with a rough surface.

Association

a community of definite composition, associated with a definite type of habitat, and recognized by the predominance of one or more floristic types, such as a damp oakwood.

Attenuate

tapering gradually to a slender point.

Auricled

of the leaves, with ear-like lobes at the base.

Autochorous

dispersed by the plant itself - of the seed.

Autonomous movement

spontaneous, not induced by external stimulus.

Awn

a bristle-like appendage, as in Grasses.

Axil

the angle of the stem and leaf.

Axis

the central stem or root.

Barbs

the recurved processes on bristles and teeth on the leaf-margin.

Bark

the external layer of the stem in woody plants where a corky layer is formed.

Bast

the inner layer of the bark, which is soft phloem, or hard bast fibres.

Beak

a prolonged point.

Bearded

furnished with long hair, like a beard.

Berry

a succulent fruit, with several seeds, soft pericarp.

Biennial

of two years' duration, flowering and producing seed the second year.

Bifid

divided into two parts half-way. Bilabiate, with two lips.

Bipartite

divided into two parts nearly entirely.

Bipinnate

tri-, quadri-, etc, 2, 3, or 4 times divided again in the case of a pinnate leaf.

Bipinnatifid

once again pinnatifid.

Biternate

a ternate leaf divided ternately again.

Bract

a leaf differing from the stem leaves situated in the floral region.

Bracteoles

small bracts on the peduncle.

Bud

an unexpanded shoot, whether on the axis or leaves.

Bulb

an underground bud with fleshy scale-leaves, stored with reserve material.

Caespitose

tufted, of roots, stems, or leaves.

Calciphilous

addicted to a lime soil.

Calyx

the outermost protective whorl of the perianth, usually green, made up of sepals.

Cambium

the layer between wood and bast, forming new (secondary) wood and bast.

Capillary

thread-like, slender.

Capitate

clustered in heads with a knob like the head of a pin.

Capitulum

a head of sessile flowers, as in Compositae.

Capsule

a dry many-seeded dehiscent fruit.

Carpel

the modified leaf which forms a single-celled ovary, or a single cell of an ovary.

Caryopsis

a one-seeded fruit in which the seed-coat and pericarp are adherent, indehiscent, as in Grasses.

Catapult fruit

a fruit in which the seed is expelled by an elastic movement of the plant itself.

Catkin

a spike of flowers of one sex only, with bracts in place of perianths.

Caulescent

with an erect stem.

Cauline

arising from the stem.

Centrifugal

growing outwards from the middle.

Centripetal

growing inwards towards the centre.

Channelled

hollowed out in the centre or middle line.

Chasmochomophyte.

Chasmophyte

plants that grow in crevices on bare rock, with a little detritus only.

Chersophytes

plant formations on waste land.

Chlorophyll

the green colouring-matter in plants which enables them to assimilate carbon by aid of the sun. Chomophytes, plants growing on rock on which detrital matter is present as a subsoil, on the surface or in crevices.

Ciliate

with a fringe of hairs.

Clavate

club-shaped.

Claw

the attenuate base or stalk of a petal.

Cleft

divided, but not so far as the midrib.

Cleistogamic

flowers that do not open and are self-pollinated.

Coherent

united together.

Column

when the stamens and style fuse to form one structure, as in Orchids.

Commensal

when a species shares, with another, food material, e.g. parasites, saprophytes.

Communities

the different members which together make up a coherent whole, possessing at the same time a general unity of character, as Heath-plants.

Compound

made up of a number of parts which are similar, as opposed to simple.

Compressed

flattened laterally.