Glossary
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A -
Prefix meaning without.

Abaxial
Located on the side away from the axis.

Achene
One-seeded, dry indehiscent fruit with a relatively thin wall in which the seed coat is not fused to the ovary wall.

Acuminate
Gradually tapering to a sharp point; point is drawn out.

Acute
Sharply pointed, but less tapering than acuminate; angle 90o or less.

Adaxial
Located on the side nearest the axis.

Adhere
To stick to.

Adherent
Sticking or clinging.

Adnate
Fusion of unlike parts (e.g., fusion of palea to the caryopsis in Bromus).

Adventitious roots
Roots developing from basal culms, nodes, or some structure other than the seed.

Adventive
A term used to denote an exotic species that has become established from chance or accidental seeding.

Aggregate
Clustered or forming a group with objects in close proximity.

Alternate
Located singly at each node. An arrangement of parts, e.g. leaves, placed at different heights along an axis.

Annual
Completing life cycle from seed to maturity to death within one year or one season.

Anther
Pollen bearing portion of the stamen.

Antrorse
Directed upward or forward toward the apex; the opposite of retrorse.

Apex
Uppermost tip of a structure.

Apices
Plural of apex.

Apical
Located at the tip.

Apiculate
Ending in a short, flexible point.

Appendage
A secondary part or a projecting part.

Appressed
Lying against an organ in the direction of the apex.

Aristate
Provided with a short awn or bristle from the apex, edge or back of an organ.

Aromatic
Having an odor, fragrant or otherwise; bearing volatile essential oils.

Articulate
Jointed; a node for natural separation.

Ascending
Sloping or rising obliquely upward.

Asexual
Without sex; sexless; not involving gametes.

Asymmetrical
Not having planes which divide the structure into mirror-image halves.

Attenuate
Gradually narrowing to a pointed apex or base; sharper than acute.

Auricle
A finger-like appendage or flange of tissue at the junction of the blade and sheath in some grasses. Holds the open sheath to the culm.

Autumnal
Growth form for late summer and fall (e.g. Dichanthelium).

Awn
The extension of the vein (nerve) of spikelet bracts beyond the leaf-like tissue.

Axil
The upper angle between an organ (branch) and its axis.

Axillary
Occurring in an axil.

Axis
The central stem(s) of an inflorescence, particularly of a panicle.