Abortive

Defective or barren.

Achene

A small, dry, hard, one-celled, and one-seeded fruit, with tightly fitting and valveless covering.

Acute

Sharp-pointed.

Alternate (leaves)

Not opposite; arranged singly at different heights on the axis.

Annual

A plant which matures fruit in one year. Anther. The part of a stamen which contains the pollen.

Appressed

Lying flatly and close against.

Ascending

Curving upward or rising obliquely.

Auricle

An ear-shaped lobe or appendage.

Awl-shaped

Tapering from the base to a rigid point.

Awn

A very slender but stiff and bristle-like appendage.

Axil

The angle formed by the junction of a leaf or branch with the stem.

Axillary

Situated in an axil.

Barbed

Tipped with sharp, rigid, and reflexed points.

Beaked

Having a tapering, prolonged tip.

Berry

A simple fruit which is wholly pulpy or fleshy except the outer skin.

Biennial

Of two years' duration.

Blade

The flat, expanded part of a leaf.

Bract

A more or less modified leaf subtending a flower, or a flower cluster, or sometimes borne on a stem.

Bulb

An underground leaf-bud with fleshy scales or coats.

Bulbous

Bearing bulbs.

Calyx

The outer floral envelope.

Canescent

Hoary with fine gray hairs.

Capillary

Hair-like.

Capitate

Shaped like a head.

Capsule

A dry fruit of two or more carpels, opening usually by valves or teeth.

Carpel

A single ovary, or one part of a compound ovary.

Cell

A cavity of an ovary or of an anther.

Ciliate

Fringed with marginal hairs.

Coma

A tuft of hairs at the end of some seeds.

Comose

Bearing tufted hairs at the apex.

Compound

Composed of similar parts forming one whole.

Compressed

Flattened laterally.

Connate

Similar structures more or less united.

Corm

The swollen, fleshy, and solid base of a stem.

Corolla

The inner floral leaves or petals, which may be distinct or more or less united.

Corymb

A convex or flat-topped flower cluster with pedicels or rays arising from different points on the axis, and with the progression of bloom from the margin inward.

Crenate

Scalloped; having rounded teeth.

Culm

The stem peculiar to grasses and sedges.

Cyme

A convex or flattened flower cluster of which the central flowers first unfold, the progression of bloom being toward the margin.

Deciduous

Not persistent; falling away at the end of the growing period.

Decumbent

Declining but with the end ascending.

Decurrent (leaf)

Extending down the stem below the insertion.

Deflexed

Turned abruptly downward.

Dehiscent

Opening regularly by valves, slits, or teeth.

Depressed

Flattened vertically.

Diffuse

Widely or loosely spreading.

Dioecious

Bearing staminate or male flowers on one plant, and fertile or pistillate flowers on another plant.

Disk

In Composites, the tubular flowers of the head as distinct from the rays.

Drupe

A fleshy or pulpy fruit having an inner portion of the pericarp hard and bone-like.

Entire

Without divisions, lobes, or teeth.

Exserted

Projecting beyond an envelope, as the stamens from a corolla.

Fascicle

A close bundle or cluster.

Fertile

Bearing fruit or seed.

Filament

The part of a stamen which supports the anther; any thread-like body.

Floret

A small flower, usually one of a head or a dense cluster.

Follicle

A fruit consisting of a single carpel, opening by the ventral or inner suture.

Fruit

The seed-bearing product of any plant, simple, compound, or aggregated, of whatever form.

Glabrous

Smooth; without hairs.

Gland

A secreting cell or structure.

Glaucous

Covered with a white or bluish-white bloom.

Globose

Nearly spherical.

Glume

One of the two outer chaffy bracts at the base of the spikelet in the grasses.

Habitat

A plant's natural place of growth.

Halberd-shaped

Like an arrow-head but with the basal lobes pointing outward instead of backward.

Herb

A plant with no persistent woody stem above the ground.

Hirsute

Bearing rather coarse, stiff hairs.

Hispid

Set with rigid or bristly hairs.

Imbricated

Overlapping.

Included

Not protruding from the surrounding envelope, as the stamens from the corolla.

Indehiscent

Persistently closed; a fruit covering without an opening.

Indigenous

Native to the region of growth.

Inflated

Bladder-like.

Inserted

Attached to or growing out of.

Internode

The portion of a stem between two nodes or joints.

Introduced

Brought from another region to the place of growth.

Involucre

A circle or whorl of bracts subtending a flower cluster, or a head, or a single flower.

Involute

Rolled inward.

Irregular

Showing inequality in size and form of similar parts.

Keeled

Centrally ridged along the back.

Leaflet

A single division of a compound leaf.

Lemma

The lower of the two bracts inclosing the flower in the grasses.

Ligule

The thin projection at the top of the sheath in grasses; the ray flowers in Composites.

Linear

Long and narrow with sides nearly parallel.

Lobe

Any segment of an organ, especially if rounded.

Lyrate

Pinnatifid, with the terminal lobe much larger than the others.

Membranous

Thin, rather soft and more or less translucent.

Monoecious

Bearing stamens and pistils in different flowers but on the same plant.

Naturalized

Not native to the region of growth.

Nectary

An organ or cavity where nectar is secreted.

Nerve

An unbranched vein or a slender rib.

Neutral

Without stamens or pistils.

Node

The part of a stem or branch at which a leaf or leaves are borne.

Oblong

Longer than broad with sides nearly parallel.

Obovate

Inversely ovate.

Obovoid

Inversely ovoid.

Obtuse

Blunt or rounded at apex.

Ovary

The part of a pistil which contains the seeds.

Ovate

Having an egg-shaped outline with the broader end at the base.

Ovoid

Egg-shaped.

Ovule

The body which after fertilization becomes the seed.

Palea

The upper of the two bracts which inclose the flower in grasses.

Palmate (leaf)

With segments radiately diverging.

Panicle

A somewhat loose and irregular compound flower cluster.

Pappus

Id Compositoe the bristles, awns, teeth, or scales which crown the achene.

Parasite

A plant which grows upon other plants and absorbs their juices.

Pedicel

The support of one of the flowers composing a flower cluster.

Peduncle

The stalk of a flower cluster or of a single flower.

Perennial

Lasting year after year.

Perfect (flower)

Having both stamens and pistils.

Perfoliate

A leaf so clasping the stem as to seem pierced by it.

Perianth

The floral envelope, sepals and petals, regarded collectively.

Persistent

Said of organs which remain attached to their place of growth after growth has ceased.

Petal

One of the divisions of the inner floral envelope or corolla.

Petiole

The footstalk of a leaf.

Pinnate (leaf)

Compound, with leaflets arranged along the sides of a common petiole.

Pinnatifid

Pinnately cleft.

Pistil

The seed-bearing organ of a flower, consisting of ovary, stigma, and style, or the latter sometimes lacking.

Pistillate

Having pistils; ordinarily used in the sense of having no stamens.

Pod

Any dry and dehiscent fruit.

Pollen

The fertilizing grains borne in the anthers.

Prickle

A sharp outgrowth from the bark of a stem, or on the surface or stalk of a leaf.

Procumbent

Lying or trailing on the ground but without rooting at the nodes.

Prostrate

Lying flat on the ground.

Pubescent

Covered with short, soft, and down-like hairs.

Raceme

An elongated simple flower cluster with each flower pedicelled.

Rachis

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

Ray

One of the flower stalks of an umbel; the strap-shaped marginal flowers in the Compositoe.

Receptacle

The more or less expanded end of the stem which bears the organs of a flower, or, in the Compositoe, the collection of flowers in a head.

Recurved

Curved downward or backward.

Reflexed

Bent abruptly downward or backward.

Regular

Having the members of each part alike in form and size.

Revolute

Rolled backward from the margin or apex.

Rib

A primary or prominent vein in a leaf.

Rootstock

An underground, bud-bearing stem.

Scape

A naked or nearly leafless flower-stalk arising directly from the crown of the root.

Scarious

Thin, dry, and membranous, not green.

Segment

One of the divisions of a lobed or cleft leaf, or other organ of a plant.

Sepal

One of the divisions of a calyx.

Serrate

With sharp, forward-pointing teeth.

Sessile

Without a footstalk of any kind.

Sheath

A tubular envelope, as the lower part of the leaf in grasses.

Silicle

A short silique.

Silique

The pod peculiar to the Cruciferoe.

Simple

Not compound.

Sinuate

Wavy-edged.

Sinus

The cleft or space between two lobes.

Spadix

A flower spike having a fleshy axis.

Spathe

A large bract or a pair of bracts inclosing a spadix or a flower cluster.

Spatulate

Narrowing gradually toward the base from a rounded apex.

Spike

An elongated flower cluster with flowers sessile or nearly so upon its axis.

Spine

A sharp and rigid outgrowth from the stem of a plant.

Spur

A tubular or sac-like extension of some part of a flower, usually nectar-bearing.

Stamen

One of the pollen-bearing organs of a flower.

Stem

The main ascending axis of a plant.

Sterile

Unproductive, as a flower without a pistil, or a stamen without an anther.

Stigma

That part of the pistil through which pollen grains penetrate and effect fertilization.

Stipe

The stalk-like support of a pistil; the leafstalk of a fern.

Stipule

An appendage at the base of a leafstalk or on each side of its insertion.

Stolon

A runner, or any basal branch which takes root at the nodes.

Striate

Marked with lengthwise lines or ridges.

Style

The (usually) slender and elongated part of a pistil connecting the ovary and stigma.

Succulent

Juicy and fleshy.

Suture

The line of splitting or opening of a dehiscent fruit.

Ternate

Arranged in threes.

Tendril

Very slender, coiling organs by which some climbing plants cling to a support.

Tomentose

Densely covered with wool-like hairs.

Truncate

Ending abruptly as if cut off squarely.

Tuber

A short, thickened, underground branch having numerous buds or "eyes".

Umbel

A flower cluster having all the pedicels arising from the same point.

Unisexual

Bearing staminate and pistillate flowers on different plants.

Utricle

The bladder-like covering of a one-seeded fruit.

Valve

One of the divisions into which a capsule splits.

Vein

Branching threads of fibrous tissue in leaves and other organs.

Viscid

Glutinous or sticky.

Whorl

Arranged in a circle around a stem.