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1 Nodes (at least the lower) densely bearded with retrorse hairs; spikelets 3.3-5.2 mm long; ligule ciliate, the membranous base minute or obsolete. |
2 Ligule 2.5-4 mm long; lower internodes pubescent with long ascending or spreading hairs; cauline blades 8-15 cm long, 10-25 mm wide; first glume 1.8-2.5 mm long |
2 Ligule 0.3-1.3 mm long; lower internodes glabrous or pubescent with ascending hairs; cauline blades 5-15 cm long, either 1-13 or 12-40 mm wide; first glume 1.2-2.2 mm long. |
3 Basal as well as cauline blades linear, 1-4 mm wide, > 30× as long as wide; spikelets 2.8-3.8 (-4.5) mm long |
3 Cauline blades narrowly lanceolate to broadly ovate- lanceolate, 4-40 mm wide, < 20× as long as wide; spikelets 3.3-5.2 mm long. |
4 Blades 12-40 mm wide, broadly ovate- lanceolate, basally cordate; spikelets 3.8-5.2 mm long, 1.7-2.2 mm wide; first glume narrowly triangular; second glume shorter than fertile lemma |
4 Blades 4-14 mm wide, narrowly lanceolate to lanceolate, basally narrowed, rounded, or subcordate; spikelets 3.3-4.5 mm long, 1.2-1.9 mm wide; first glume broadly ovate to triangular; second glume 0.0-0.5 mm longer than fertile lemma. |
5 Lowest elongate internode puberulent to glabrous; lower culm sheaths shorter than internodes, upper culm sheaths longer; blades lanceolate, about 10× as long as wide; blade bases narrowly rounded to subcordate; spikelets 3.3-4.0 mm long, blunt to acute; first glume broadly ovate; second glume equaling or exceeding fertile lemma by 0.2 mm |
5 Lowest elongate internode moderately to densely papillose- pubescent with spreading to ascending hairs; all culm sheaths shorter than internodes; blades narrowly lanceolate, about 15× as long as wide; blade bases narrowed; spikelets 3.5-4.5 mm long, beaked; first glume triangular to ovate; second glume exceeding fertile lemma by 0.2-0.5 mm |
1 Nodes glabrous, pubescent, or sparsely pilose; spikelets (2.4-) 3.3-4.2 mm long; ligules membranous, ciliate, or both. |
6 Ligule 1.6-3 mm long; blades 4-9 mm wide, > 10× as long as wide |
6 Ligule 0.2-1.5 mm long; if larger blades < 9 mm wide and mostly 15× or more as long, then ligule 0.5-1 mm long. |
7 Larger blades 2-6 (-8) mm wide, 10-15× or more as long as wide (if shorter, then culms arising from hard corm-like bases and culms with 8-14 leaves); spikelets basally attenuate. |
8 Culm bases not corm-like; blades usually 15× or more as long as wide, their bases narrowed; vernal panicle usually matures before development of primary branches; upper glume and sterile lemma exceeding fertile lemma, beak-like |
8 Culm bases hard, corm-like; blades usually 10-15× as long as wide, their bases rounded to truncate; primary branches usually develop before maturation of vernal panicle; upper glume about 0.3 mm shorter than fertile lemma, sterile lemma about equaling fertile lemma. |
9 Cauline leaves 8-14; blades thick, puberulent, parallel-sided proximally; ligule of cilia only; vernal panicles 3-13 × 2-8 cm; pedicels ± appressed; lower glumes deltoid, bases fully encircling pedicel |
9 Cauline leaves 4-7; blades thin, glabrous to sparsely hirsute, widening proximally; ligule a ciliate membrane; vernal panicles 3-6 × 2-4 cm; pedicels ± divergent; lower glumes narrowly triangular, bases partially encircling pedicel |
7 Larger blades 6-35 mm wide, mostly 10× or less as long as wide; spikelet bases rounded to narrowed. |
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10 Spikelets glabrous to pubescent with hairs < 0.5 mm long; blades glabrous, scabrous, or pubescent. |
11 Spikelet apex acute; second glume and sterile lemma exceeding fertile lemma by 0.3-0.8 mm |
11 Spikelet apex rounded to sub- acute; second glume and sterile lemma equaling or shorter than fertile lemma. |
12 Ligules 1-1.5 mm long; blades 5-10 cm long by 6-15 mm wide, glabrous or pubescent, basally rounded; spikelets glabrous to pubescent |
12 Ligules 0.3-1 mm long; blades 7-35 cm long by 8-35 mm wide, glabrous or scabrous, basally cordate or rounded; spikelets pubescent to glabrate. |
13 Sheaths (at least lower) papillose- hispid with spreading hairs; ligule 0.5-1.2 mm long, an eciliate membrane; culm blades 10-28 cm long; spikelets 2.4-3.6 mm long; first glume 1.2-1.8 mm long |
13 Sheaths glabrous or pubescent (the upper papillose- pubescent in D. xanthophysum); ligules 0-0.7 mm long, ciliate if more than 0.3 mm long; culm blades 5-18 cm long; spikelets 2.2-4.1 mm long; first glume 0.7-2.6 mm long. |
14 Upper sheaths glabrous to softly villous basally; ligules 0.4-0.7 mm long, a short- ciliate membrane; culm blades 15-40 mm wide, the bases cordate- clasping; panicle usually more than half as wide as long |
14 Upper sheaths glabrous, puberulent, or papillose- pubescent; ligules 0-0.5 mm long, eciliate or ciliate; culm blades 5-25 mm wide, the bases cordate- clasping or rounded; panicles less or more than half as wide as long. |
15 Upper sheaths glabrous or puberulent; ligules 0-0.3 mm long, eciliate; culm blades cordate- clasping; panicles usually more than half as wide as long; spikelets 3.3-3.7 mm long, ellipsoid, apex obtuse to pointed |
15 Upper sheaths papillose- pubescent; ligules 0.3-0.5 mm long, ciliate; culm blade bases rounded; panicles usually less than half as wide as long; spikelets 3.2-4.1 mm long, obovoid, blunt |