Flora of the Southeastern United States
2022 Edition

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Key to Dichanthelium, Key C: Spikelets 2.1-3.2 mm long, larger leaves 13-25 mm wide

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1 Culm nodes, at least the lower, bearded (often retrorsely).
..2 Nodes with a viscid band below the beard; internodes and sheaths velvety-pubescent; vernal culm blades 9-20 cm long, 9-20 mm wide
..2 Nodes without a viscid band below the beard; internodes and sheaths glabrous, the lower sometimes sparsely hairy; vernal culm blades 3.5-14 cm long, 7-15 mm wide
1 Culm nodes glabrous or pubescent, but not bearded.
....3 Second glume and sterile lemma acute to short-acuminate, some in a given specimen 0.3 mm or more longer than fertile lemma.
......4 Ligule an eciliate membrane; peduncle scabrous; first glume 0.3-0.6 (-0.8) mm long, reniform to suborbicular
......4 Ligule a ciliate membrane or entirely ciliate; peduncle smooth; first glume 0.7-1.6 mm long, broadly ovate to lanceolate.
........5 Ligule a ciliate membrane; larger leaves 10-20 cm long; spikelets pubescent, (2.6-) 2.8-3.4 (-3.6) mm long; first glume (0.9-) 1.0-1.6 mm long
........5 Ligule entirely ciliate; larger leaves 9-14 cm long; spikelets glabrous, 2.1-2.6 mm long; first glume 0.7-1.2 mm long
....3 Second glume and sterile lemma blunt to subacute, shorter than, equaling, or barely exceeding fertile lemma, never by as much as 0.3 mm.
..........6 Ligule ciliate, 0.2-1.1 (-2.1) mm long; leaf blades 5-14 cm by 5-17 mm; second glume 0-0.3 mm shorter than fertile lemma.
............7 Culms 30-75 cm long; lower sheaths glabrous to sparsely papillose-pilose; panicle pulvini glabrous to sparsely pilose; spikelets 1.8-2.6 mm long; first glume narrowly triangular (triangular-ovate); second glume 0-0.1 mm shorter than fertile lemma
............7 Culms 60-150 cm long; lower sheaths papillose-pilose; panicle pulvini pubescent; spikelets 2.2-2.8 (-3.0) mm long; first glume broadly ovate; second glume 0.05-0.3 mm shorter than fertile lemma
..........6 Ligule a ciliate or eciliate membrane 0.3-0.9 mm long; leaf blades 5-28 cm by 5-40 mm; second glume 0-0.1 mm shorter than fertile lemma.
..............8 Lower sheaths papillose-hispid with spreading hairs; ligule a membrane 0.4-0.9 mm long; leaf blades 10-28 cm long
..............8 Lower sheaths glabrous, puberulent, or softly villous basally; ligule either a membrane 0-0.3 mm long or a ciliate membrane 0.4-0.7 mm long; leaf blades 5-18 cm long.
................9 Ligule a ciliate membrane 0.4-0.7 mm long; leaves 15-40 mm wide; spikelets 1.6-2.0 mm wide
................9 Ligule a membrane 0-0.3 mm long; leaves 5-25 mm wide; spikelets 1.1-1.3 mm wide
..................10 Cauline blades 5-18 cm long, 6-14 mm wide, averaging about 10 × as long as wide, the margins nearly parallel; spikelets 2.9-3.7 mm long; first glumes 1.1-2.6 mm long, 2/5 or more as long as the spikelets
..................10 Cauline blades 7-12 cm long, (6-) 12-25 mm wide, ovate-lanceolate, averaging about 6 × as long as wide, the margins curved most of their length; spikelets 2.0-3.2 mm long; first glumes 0.5-1.0 mm long, about 1/4 as long as spikelets.
....................11 Culms erect; blades more nearly symmetrical; spikelets 2.0-3.2 mm long; sterile lemma apex usually blunt to rounded
....................11 Culms basally decumbent; blades strongly asymmetrical-falcate; spikelets 3.0-3.2 mm long; sterile lemma apex usually pointed

Key to Dichanthelium, Key D: Spikelets 2.1-3.2 mm long, larger culm blades < 13 mm wide,
at least the lower culm nodes bearded with a usually spreading-ascending collar of dense and/or longish hairs

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1 Ligule with a dense ring of short hairs 0.5-1 mm long, and behind it a ring of longer hairs 1-5 mm long called the pesudoligule (see introduction for discussion of the so-called double ligule).
..2 Culms > 100 cm long; lower and mid culm blades 12-20 cm, about 20× as long as wide; mature vernal panicles 9-14 cm long, about 2× as long as wide; upper glumes exceeding fertile lemmas by about 0.2 mm
..2 Culms > 100 cm long; lower and mid culm blades 12-20 cm, about 20× as long as wide; mature vernal panicles 9-14 cm long, about 2× as long as wide; upper glumes exceeding fertile lemmas by about 0.2 mm.
....3 Plants velvety-pubescent throughout; nodes retrorsely bearded; internode pubescence retrorse to spreading; blades usually ciliate above base as well as basally; mature vernal panicles 3-7 cm long, 2-5 cm wide, about 2/3 as wide as long
....3 Plants densely pubescent to glabrate, but lacking velvety pubescence; nodes with spreading to ascending pubescence (sometimes retrorse in D. villosissimum); internode pubescence ascending, appressed, or spreading; blades ciliate only at base (sometimes appearing ciliate laterally in D. ovale var. ovale); mature vernal panicles 4-10 cm long, nearly or equally as wide.
......4 Lower internodes with retrorse or spreading hairs to 3+ mm long; blade adaxial surface pilose with hairs to 4+ mm long, these appressed and angled away from the leaf axis; spikelets 2.1-2.5 mm long
......4 Lower internodes pilose with (spreading-) ascending to appressed hairs, or nearly glabrous; blade adaxial surface sparsely appressed-pubescent to glabrate; spikelets 2.1-3.1 mm long.
........5 Culm blades 3-8 mm wide, usually sparsely appressed-pubescent on both surfaces, eciliate or ciliate at base only; spikelets 2.1-2.5 mm long
........5 Culm blades 3-8 mm wide, usually sparsely appressed-pubescent on both surfaces, eciliate or ciliate at base only; spikelets 2.1-2.5 mm long
1 Ligule a single structure, without a pseudoligule.
..........6 Ligule 2-5 mm long, ciliate
..........6 Ligule < 2 mm long, ciliate or membranous.
............7 Ligule a stramineous to light brown membrane, with or without terminal cilia; peduncle antrorsely scabrous but not hairy.
..............8 Panicle rachis smooth, pellucid-punctate; first glume 0.3-0.6 (-0.8 ) mm long, as broad as or broader than long, truncate to obtuse; larger leaves 10-25 cm long, 8-15 mm wide; ligule 0.5-1.3 mm long; lowest elongate culm internode > 2 mm in diameter; lowest nodes usually glabrous or pubescent
..............8 Panicle rachis scabrous or smooth, not pellucid-punctate; first glume 0.5-1.1 mm long, longer than wide, rounded to acute; larger leaves 3.5-12 cm long, 3-9 mm wide; ligule 0.1-0.6 mm long; lowest elongate culm internode < 2 mm in diameter; lowest nodes retrorsely bearded or glabrous.
................9 Lowest nodes usually retrorsely bearded; ligules (0.1-) 0.3-0.6 mm long; largest vernal blades 7-12 cm long, (4.5-) 6-9 mm wide; panicle peduncle scabrous; spikelets ovate-lanceolate, acute, 2.0-2.4 mm long; first glume lanceolate, blunt to acute; fertile lemma smooth
................9 Lowest nodes usually glabrous; ligules 0.1-0.2 (-0.3) mm long; largest vernal blades 3.5-7 cm long, 3-6 mm wide; panicle peduncle smooth; spikelets elliptic, blunt to acute, 1.6-2.2 mm long; first glume ovate to rotund, rounded to acute; fertile lemma papillose
............7 Ligule entirely of white hairs; peduncle variously hairy or glabrous, but not antrorsely scabrous.
..................10 Culms with a viscid band below the retrorsely bearded nodes; internodes, sheaths, and blades velvety-pubescent
..................10 Culms without a viscid band below the retrorsely, spreading, or antrorsely bearded nodes; internodes and sheaths not velvety-pubescent, blades velvety-pubescent in some.
....................11 Blades (15-) 20× or more as long as wide, increasing in length upwards on culm; blade adaxial surface (weakly-) strongly scabrous; sheaths glabrous; second glume and sterile lemma exceeding fertile lemma
....................11 Blades < 15× as long as wide, similar or more often decreasing in size upwards on culm (if increasing, then sheaths strongly retrorsely pilose in D. laxiflorum); blade adaxial surface smooth to moderately scabrous; second glume and sterile lemma shorter than to exceeding fertile lemma.
......................12 Nodes retrorsely bearded; larger vernal leaves 7-15 mm wide.
........................13 Sheaths retrorsely pilose with hairs 2-3 mm long; basal leaves usually numerous, ascending, similar in size and shape to the culm leaves; culms branching only at the base in autumnal phase
........................13 Sheaths glabrous or pilose (if pilose, then hairs not both retrorse and 2-3 mm long); basal leaves rosette-forming, usually much shorter than culm leaves; culms branching above base in autumnal phase.
..........................14 Plants rarely > 1 m in length; lower internodes glabrous to sparsely hairy; vernal cauline leaves 3-7; spikelets 1.8-2.8 mm long, elliptic to lance-ovate, blunt to acute, glabrous or pubescent
..........................14 Plants often > 1 m in length; lowest internodes moderately to densely villous; vernal cauline leaves 6-15; spikelets 1.8-2.2 mm long, obovoid to broadly ellipsoid, rounded to blunt, pubescent
......................12 Nodes spreading to antrorsely bearded; larger vernal leaves 3-10 mm wide.
............................15 Culm internodes glabrous to sparsely pilose; culm nodes bearded with long retrorse hairs; blade surfaces glabrous to velvety-pubescent
............................15 Culm internodes, at least the lower, strigose, pilose, or villous; culm nodes bearded with ascending or spreading hairs; blade surfaces glabrous or variously hairy.
..............................16 Lower nodes bearded with erect-ascending, soft, and long hairs; mid-culm blades usually 20× or more as long as wide.
................................17 Spikelets (3.0-) 3.2-3.8 mm long, fusiform, pointed at summit, attenuate at base, with both glumes attached 0.3-0.5 mm below sterile lemma, the autumnal spikelets 3.5-3.8 mm long; larger vernal blades 3-6 mm wide, the lower and mid-culm blades of similar width; autumnal blades involute
................................17 Spikelets 1.8-3.1 mm long, obovate, blunt, and the base not attenuate except in D. arenicoloides with autumnal spikelets 2.3-3.1 mm long; larger vernal blades 2-8 mm wide, the lower usually wider and often shorter than mid-culm blades; autumnal blades involute or flat.
..................................18 Longest vernal blades to 16 cm, widest vernal blades 4-8 mm, usually longitudinally wrinkled; vernal and autumnal spikelets 2.3-3.1 mm long; autumnal blades flat, the larger to 9 cm × 2-4 mm
..................................18 Longest vernal blades to 6 (D. aciculare) or 12 (D. arenicoloides) cm long, 2-5 mm wide, not noticeably wrinkled; vernal spikelets 1.5-2.8 mm long, autumnal spikelets either 1.5-2.3 (D. aciculare) or 2.3-3.1 (D. arenicoloides); autumnal blades involute, the larger to 6 cm × 1.5 mm.
....................................19 Longest vernal blades to 6 (-8) cm, widest vernal blades 2-5 mm; vernal and autumnal spikelets 1.7-2.3 mm long, blunt, not attenuate, the glumes attached <0.2 mm below sterile lemma; first glumes 0.6-0.9 mm long; larger autumnal blades to 3 cm by 1 mm
....................................19 Longest vernal blades to 12 cm, widest vernal blades 3-4 (-5) mm; vernal spikelets 2.1-2.8 mm long; autumnal spikelets 2.3-3.1 mm long, pointed, attenuate, the glumes attached 0.3-0.5 mm below sterile lemma; first glumes 0.7-1.5 mm long; larger autumnal blades to 6 cm by 1.5 mm
..............................16 Lower and often mid-culm nodes bearded with spreading, stiffish, and short-to-long hairs; mid-culm blades usually 15× or less as long as wide.
......................................20 Blades stiff, often longitudinally ribbed, at least the lower villous or strongly pilose on the abaxial surface, and pilose to hirsute on the adaxial surface, at least proximally.
........................................21 Spikelets 2.3-3.0 mm long; ligule < 1 mm long; mid-culm blades 4-8 mm wide
........................................21 Spikelets 1.7-2.0 (-2.3) mm long; ligule 1-2.5 mm long; mid-culm leaves 2-5 mm wide
......................................20 Blades not noticeably stiff nor longitudinally ribbed, pubescent or strigose underneath, glabrous above or with a few long hairs near the base.
..........................................22 Spikelet bases strongly attenuate, apices blunt to beaked; first glume (2/5-) ½-2/3 (-4/5) as long as spikelet, attached 0.3-0.5 (-0.7) mm belong expansion of second glume and sterile lemma; larger vernal blades 3-6 (-7) mm wide
..........................................22 Spikelet bases not noticeably attenuate, apices rounded to obtuse; first glume < ½ as long as spikelet, attached < 0.3 mm below expansion of second glume and sterile lemma; larger vernal blades 5-12 mm wide.
............................................23 Culms 50-140 cm long; lowest internodes usually purplish; leaf sheaths often viscid-spotted; leaf blades glabrous abaxially, glabrous and scabrous adaxially; spikelets 1.8-2.2 mm long
............................................23 Culms 15-60 cm long; lowest internodes usually olive- or bluish-green; leaf sheaths not viscid-spotted; leaf blades appressed-pubescent abaxially, glabrous and smooth to appressed pubescent adaxially; spikelets 2.1-3.1 mm long.
..............................................24 Spikelets 2.5-3.1 mm long; lower culm blades usually glabrous adaxially except for long hairs at or near the margin (appearing ciliate), appressed-pubescent abaxially
..............................................24 Spikelets 2.1-2.6 mm long; lower culm blades usually sparsely appressed-pubescent on both surfaces, eciliate or ciliate at the base only

Key to Dichanthelium, Key E: Spikelets 2.1-3.2 mm long, larger culm blades < 13 mm wide, culm nodes not bearded,
the lowermost sometimes puberulent or sparsely pilose

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1 Ligule 1.6-4 mm long
1 Ligule < 1.5 mm long.
..2 Leaf blades, at least the lower, cordate or subcordate at the base, 4-25 mm wide.
....3 Culm blades 4-12 mm wide; spikelets obpyriform when viewed dorsally, strongly plano-convex when viewed laterally, usually markedly reddish-purple basally; fertile lemma papillose
....3 Culm blades 5-25 mm wide; spikelets elliptic to elliptic-obovoid when viewed dorsally or laterally, greenish to faintly purple-tinged basally; fertile lemma not papillose.
......4 Ligule ciliate, 0.2-0.8 mm long; culm blades 5-14 mm wide; spikelets 1.8-2.6 mm long; first glumes 0.5-1 mm long
......4 Ligule an eciliate membrane 0-0.3 mm long; culm blades 5-25 cm wide; spikelets 2.0-3.7 mm long; first glumes 0.5-2.6 mm long.
........5 Internodes crisp-puberulent; larger culm blades 4-8 (-11) cm long, 5-10 (-12) mm wide, broadest near the base; spikelets 2.1-2.7 mm long; first glumes 0.7-0.9 mm long
........5 Internodes glabrous to sparsely pubescent, larger culm blades 5-18 cm long, 5-25 mm wide, broadest near the middle or broadly linear; spikelets 2.0-3.7 mm long; first glumes 0.5-2.6 mm long.
..........6 Cauline blades 5-18 cm long, 6-14 mm wide, averaging about 10 × as long as wide, the margins nearly parallel; spikelets 2.9-3.7 mm long; first glumes 11-26 mm long, 2/5 or more as long as the spikelets
..........6 Cauline blades 7-12 cm long, (6-) 12-25 mm wide, ovate-lanceolate, averaging about 6 × as long as wide, the margins curved most of their length; spikelets 2.0-3.2 mm long; first glumes 5-10 mm long, about 1/4 as long as spikelets.
............7 Culms erect; blades more nearly symmetrical; spikelets 2.0-3.2 mm long; sterile lemma apex usually blunt to rounded
............7 Culms basally decumbent; blades strongly asymmetrical-falcate; spikelets 3.0-3.2 mm long; sterile lemma apex usually pointed
..2 Leaf blades tapering to the base, 2-12 mm wide.
..............8 Ligule a stramineous to light brown membrane, with or without terminal cilia.
................9 Ligule a ciliate membrane; spikelets (2.6) 2.8-3.4 (3.6) mm long; first glume (0.9) 1.1-1.6 mm long
................9 Ligule an eciliate membrane; spikelets 1.6-2.8 (3.0) mm long; first glume 0.3-1.1 mm long.
..................10 Panicle rachis smooth, pellucid-punctate; first glume 0.3-0.6 (-0.8 ) mm long, as broad as or broader than long, truncate to obtuse; larger leaves 10-25 cm long, 8-15 mm wide; ligule 0.5-1.3 mm long; lowest elongate culm internode > 2 mm in diameter; lowest nodes usually glabrous or pubescent
..................10 Panicle rachis scabrous or smooth, not pellucid-punctate; first glume 0.5-1.1 mm long, longer than wide, rounded to acute; larger leaves 3.5-12 cm long, 3-9 mm wide; ligule 0.1-0.6 mm long; lowest elongate culm internode < 2 mm in diameter; lowest nodes retrorsely bearded or glabrous.
....................11 Lowest nodes usually retrorsely bearded; ligules (0.1-) 0.3-0.6 mm long; largest vernal blades 7-12 cm long, (4.5-) 6-9 mm wide; panicle peduncle scabrous; spikelets ovate-lanceolate, acute, 2.0-2.4 mm long; first glume lanceolate, blunt to acute; fertile lemma smooth
....................11 Lowest nodes usually glabrous; ligules 0.1-0.2 (-0.3) mm long; largest vernal blades 3.5-7 cm long, 3-6 mm wide; panicle peduncle smooth; spikelets elliptic, blunt to acute, 1.6-2.2 mm long; first glume ovate to rotund, rounded to acute; fertile lemma papillose
..............8 Ligule of short white hairs or absent.
......................12 Leaves basally disposed, usually matted or cushion-forming, larger than the mid and upper culm leaves; blade margins uniformly papillose-ciliate; culms branching only at the base, 0.5-3.5 dm tall; internodes glabrous or sparsely pubescent
......................12 Basal leaves usually rosette-forming, not matted or cushion-forming, usually much smaller than culm leaves; blade margins glabrous, or ciliate only below the middle (or sometimes papillose-ciliate throughout in D. portoricense ssp. patulum, which has densely puberulent internodes); culms branching at the nodes in age, 1.5-7.5 dm tall.
........................13 Blades progressively longer upwards on culm, the larger 9-20 cm long and 3-8 mm wide, (15-) 20 × or more as long as wide, firm but not stiff, not longitudinally grooved or wrinkled; blade adaxial surface (weakly-) strongly scabrous; sheaths glabrous; second glume and sterile lemma exceeding fertile lemma
........................13 Blades similar or more often decreasing in size upwards on culm, the larger 3-16 cm long and 2-25 mm wide; if 15 × or more as long as wide, then blades stiff and longitudinally grooved or wrinkled (sect. Angustifolia); blade adaxial surface smooth to moderately scabrous; sheaths glabrous or pilose; second glume and sterile lemma shorter than to exceeding fertile lemma.
..........................14 Blades of mid-culm leaves typically long and stiff, acuminate, linear or narrowly lanceolate, usually > 10× as long as wide, only 2-6 mm wide when < 8 cm long.
............................15 Vegetative parts glabrous (spikelets pubescent, lowest internodes and sheaths sometimes sparsely pubescent, blades and sheaths sometimes ciliate); mature panicles less than ¼ as wide as long, the branches erect-ascending, the spikelets often subsecund; autumnal blades 4-10 cm long, involute, < 2 mm wide; spikelets 1.8-2.2 mm long.
..............................16 Larger vernal blades 5-8 cm long and 3-5 mm wide; vernal panicles usually less than ¼ as wide as long, spikelets often subsecund along the strongly ascending to erect branches; spikelets 1.8-2.2 mm long, second glume and sterile lemma pubescent, summits blunt, about equaling fertile lemma; [of coastal wetlands and Piedmont prairies from NC and AR south to the Caribbean and Central America]
..............................16 Larger vernal blades 5-9 cm long and 2-3 mm wide; vernal panicles usually ¼ to ½ as wide as long, the branches ascending; spikelets 2.3-3.0 mm long, second glume and sterile lemma sparsely pubescent to glabrous, summits pointed to blunt, exceeding fertile lemma; [of c. and s. FL]
............................15 Vegetative parts pubescent, at least in the lower portion of plant; mature panicles usually more than half as wide as long, the branches spreading-ascending, the spikelets not noticeably subsecund; autumnal blades 1-6 cm long, involute and < 2 mm wide in D. aciculare and D. arenicoloides, or to 9 cm long, flat and 2-4 mm wide in D. angustifolium (autumnal blade dimensions not yet known for D. wilcoxianum); spikelets 1.5-3.2 mm long.
................................17 Culms 15-35 cm long; all culm leaf blades long-hirsute on both surfaces, their sheaths densely papillose-hirsute; leaf blades of the primary branches often exceeding the immature vernal panicles
................................17 Culms 15-75 cm long; culm leaf blades glabrous to sparsely pubescent, or the lower softly villous abaxially in D. arenicoloides; lower sheaths usually villous, mid-culm and upper sheaths glabrous (though often ciliate basally); leaf blades of primary branches not exceeding immature vernal panicles.
..................................18 Spikelets (3.0-) 3.2-3.8 mm long, fusiform, pointed at summit, attenuate at base, with both glumes attached 0.3-0.5 mm below sterile lemma, the autumnal spikelets 3.5-3.8 mm long; larger vernal leaf blades 3-6 mm wide, the lower and mid-culm leaf blades of similar width; autumnal leaf blades involute
..................................18 Spikelets 1.8-3.1 mm long, obovate, blunt, and the base not attenuate (except in D. arenicoloides with autumnal spikelets 2.3-3.1 mm long); larger vernal leaf blades 2-8 mm wide, the lower usually wider and often shorter than mid-culm leaf blades; autumnal leaf blades involute or flat.
....................................19 Longest vernal blades to 16 cm, widest vernal leaf blades 4-8 mm, usually longitudinally wrinkled; vernal and autumnal spikelets 2.3-3.1 mm long; autumnal leaf blades flat, the larger to 9 cm by 2-4 mm
....................................19 Longest vernal leaf blades to 6 cm (D. aciculare ) or 12 cm (D. arenicoloides) long, 2-5 mm wide, not noticeably wrinkled; vernal spikelets 1.5-2.8 mm long, autumnal spikelets either 1.5-2.3 (D. aciculare) or 2.3-3.1 (D. arenicoloides); autumnal leaf blades involute, the larger to 6 cm by 1.5 mm.
......................................20 Longest vernal leaf blades to 12 cm, widest vernal leaf blades 3-4 (-5) mm; vernal spikelets 2.1-2.8 mm long; autumnal spikelets 2.3-3.1 mm long, pointed, attenuate, the glumes attached 0.3-0.5 mm below sterile lemma; first glumes 0.7-1.5 mm long; larger autumnal leaf blades to 6 cm by 1.5 mm
......................................20 Longest vernal leaf blades to 6 (-8) cm, widest vernal leaf blades 2-5 mm; vernal and autumnal spikelets 1.7-2.3 mm long, blunt, not attenuate, the glumes attached < 0.2 mm below sterile lemma; first glumes 0.6-0.9 mm long; larger autumnal leaf blades to 3 cm by 1 mm
..........................14 Blades of mid-culm leaves lanceolate, thin or firm but not stiff, usually < 10× as long as wide, usually 7 mm or more wide when as much as 8 cm long.
........................................21 Spikelet bases strongly attenuate, apices blunt to beaked; first glume (2/5-) ½-2/3 (-4/5) as long as spikelet, attached 0.3-0.5 (-0.7) mm belong expansion of second glume and sterile lemma
........................................21 Spikelet bases not noticeably attenuate, apices rounded to acute; first glume < ½ as long as spikelet, attached < 0.3 mm below expansion of second glume and sterile lemma.
..........................................22 Spikelets 2.9-3.8 mm long, broadly elliptic, rounded at the summit, with broad and thick nerves
..........................................22 Spikelets 2.1-2.9 mm long, elliptic or obovate, rounded or pointed at the summit, the nerves often raised, but not broad and thick.
............................................23 Culm internodes and sheaths glabrous or, sparsely pilose, or villous.
..............................................24 Culms 50-150 cm long; at least lowest sheaths papillose-pilose.
................................................25 Lowest internodes usually purple-villous; nodes retrorsely (-spreading) bearded; spikelets 1.8-2.2 mm long, moderately densely pubescent; first glume broadly ovate, subacute, 0.4-0.7 mm long, usually < 1.5 × as long as wide; second glume about as long as sterile and fertile lemmas; fertile lemma 1.7-1.8 mm long
................................................25 Lowest internodes glabrous or pubescent or spreading villous, usually not purplish; nodes glabrous, sparsely pubescent to sparsely bearded; spikelets 2.2-2.8 (-3.0) mm long, sparsely pubescent; first glume 0.7-1.1 mm long, usually > 1.5 × as long as wide; second glume shorter than sterile and fertile lemmas; fertile lemma 2.1-2.2 mm long
..............................................24 Culms 18-100 cm long; sheaths glabrous or the lowest softly pubescent but not papillose-pilose.
..................................................26 Spikelets strongly plano-convex when viewed laterally, obpyriform when viewed dorsally, 2.2-2.6 mm long; fertile lemma and palea papillose; first glume and base of second glume usually strongly reddish-purple
..................................................26 Spikelets biconvex to elliptic when viewed laterally, variously shaped but not obpyriform when viewed dorsally; fertile lemma and palea smooth or reticulate (or papillose in D. lucidum with weak and sprawling culms and spikelets 1.7-2.3 mm long); first and second glume various
............................................23 Culm internodes crisp-puberulent (sparsely so in D. webberianum); sheaths puberulent or glabrous.
....................................................27 Spikelets elliptic, sub-acute to pointed, greenish or faintly purple-tinged basally
....................................................27 Spikelets strongly plano-convex when viewed laterally, obpyriform when viewed dorsally, broadly rounded, usually markedly reddish-purple basally.
......................................................28 Fertile lemma and palea papillose; spikelets 2.2-2.6 mm long; lower culm blades 6-12 mm wide, glabrous
......................................................28 Fertile lemma and palea smooth (minutely reticulate but not papillose); spikelets (1.8) 1.9-2.2 (-2.5) mm long; lower culm blades 2-8 mm wide, glabrous, glabrate, or puberulent (especially abaxially)