Flora of North America species comparison

2-70 cm, erect or ascending.

annual, not woody, not branching above the base;

internodes usually hollow, rarely solid.

closed, margins united for most of their length;

collars without tufts of hair on the sides;

auricles sometimes present;

ligules membranous, sometimes shortly ciliate, those of the upper and lower cauline leaves usually similar;

pseudopetioles absent;

blades linear to narrowly lanceolate, venation parallel, cross venation not evident, without arm or fusoid cells, cross sections non-Kranz, epidermes without microhairs, not papillate.

1-13 cm long, 1-4 cm wide, erect, usually ovoid, open, becoming dense, occasionally reduced to 1 or 2 spikelets;

branches shorter than the spikelets, ascending to erect, straight or almost so.

usually terminal panicles, sometimes reduced to racemes in depauperate plants;

disarticulation above the glumes and beneath each floret.

(11)14-20(23) mm, lanceolate, terete to moderately laterally compressed;

florets 5-10, bases concealed at maturity;

rachilla internodes concealed at maturity.

5-80 mm, not viviparous, terete to laterally compressed, with 3-30 bisexual florets, distal florets sometimes reduced;

rachillas prolonged beyond the bases of the distal florets.

pilose or glabrous;

lower glumes 5-7 mm, 3-5-veined;

upper glumes 6.5-8 mm, 5-7-veined;

lemmas 6.5-11 mm long, 3-5 mm wide, lanceolate, chartaceous, antrorsely pilose to pubescent, or glabrous proximally or throughout, 7-9-veined, lateral veins prominently ribbed, rounded over the midvein, hyaline margins abruptly or bluntly angled, not inrolled at maturity, apices acute, bifid, teeth shorter than 1 mm;

awns 6-8 mm, usually arising less than 1.5 mm below the lemma apices, straight to recurved at maturity;

anthers 0.6-1.5 mm.

usually unequal, rarely more or less equal, exceeded by the distal florets, usually longer than 1/4 the length of the adjacent florets, lanceolate, 1-9(11)-veined;

florets terete to laterally compressed;

calluses glabrous, not well developed;

lemmas lanceolate to ovate, rounded or keeled over the midvein, herbaceous to coriaceous, 5-13-veined, veins converging somewhat distally, apices usually minutely bilobed to bifid, rarely entire, usually awned, sometimes unawned, awns unbranched, terminal or subterminal, usually straight, sometimes geniculate;

paleas usually shorter than the lemmas;

lodicules 2, glabrous, not veined;

anthers 3;

ovaries with hairy apices;

styles 2, bases free.

equaling or shorter than the paleas, thin, weakly inrolled to flat.

narrowly ellipsoid to linear, longitudinally grooved;

hila linear;

embryos about 1/6 the length of the caryopses.

sheaths densely, often retrorsely, pilose;

upper sheaths pubescent or glabrous;

ligules 1-1.5 mm, hairy, obtuse, erose;

blades 2-19 cm long, 1-4 mm wide, abaxial surfaces glabrous or hairy, adaxial surfaces hairy.

= 7.

= 28.