Description

Key Characters:

Growth Form: Perennials or annuals, ± rhizomatous or occasionally woody and ± arborescent.

Stems:

Roots: Fibrous root system.

Leaves: Leaves simple. Alternate, distichous, rarely spirally arranged. Blades differentiated into an open or somewhat closed sheath that clasps the culm, and a blade; usually with a membranous ligule at juncture of blade and sheath, the ligule sometimes represented as a row of hairs, sometimes base of blade or apex of sheath with a pair of auricles.blades linear to elliptic or sometimes ovate. Margins usually entire. Veins parallel. Sheathing, sheath and blade encircling the culm or branch; sheaths usually open, sometimes closed, the margins fused for all or part of their length. Stipules absent.

Flowers: Flowers bisexual (perfect) or rarely unisexual, wind–pollinated or self–pollinating, cleistogamous or apomictic, 1 to numerous florets grouped together into spikelets; spikelets arranged in common panicles, racemes, spikes, or heads, each one distichously organized, consisting of a rachis bearing scaly bracts, the usually present 2 lowermost bracts (glumes) not flower–bearing and subtending 1 or more florets on opposite sides of an often zigzag axis (rachilla); each floret usually consisting of a pair of subopposite, enclosing or subtending scales (lemma and palea), above these scales on the rachilla the floret developing radial symmetry, having 2(3) small, usually fleshy scales (lodicules) borne on the rachilla between stamens, all or parts of florets often reduced or absent; outer and lower floret scale (lemma) usually 1–nerved to several–nerved, the midnerve often produced beyond the apex as an awn, either from the apex or dorsal face; inner and upper floret scale (palea) placed with dorsal face to rachilla, and usually enfolded by and shorter than the lemma, usually with 2 principal nerves. Stamens (1–)3 (–6), basifixed, but deeply sagittate and appearing versatile, dithecal, opening by longitudinal slits, rarely with a tuft of short hairs at apex. Ovary superior, probably of a single carpel, but possibly 2–3-carpellate, 1-celled; ovule 1, subapical to subbasal, orthotropous to hemitropous; stigmas 2(3), +/- large and feathery, distinct or connate.

Fruit: Caryopsis; sometimes follicular; nutlike or berry-like. Seeds usually with abundant endosperm; embryo straight; laterally adjoining endosperm.

Ploidy:

Habitat:

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