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1 Spikelets 2.4-4.5 mm long. |
..2 Nodes, internodes, and sheaths glabrous; blades 4-13 cm long, 5-8 mm wide, the surfaces smooth, glabrous; spikelets 2.4-2.9 mm long, glabrous; not known to produce axillary (autumnal) inflorescences |
..2 Nodes bearded or otherwise pubescent; internodes and sheaths variously pubescent to glabrate; blades 6-35 cm long, 2-6 mm wide, one or both surfaces scabrous and often pubescent; spikelets 1.7-4.5 mm long, glabrous or pubescent; plants produce axillary (autumnal) inflorescences. |
....3 Spikelets 2.8-3.8 (-4.5) mm long, the second glume and sterile lemma pointed or beaked and extended beyond the summit of the fertile lemma; first glume 1.2-2 mm long |
....3 Spikelets 1.7-2.8 mm long, the second glume and sterile lemma blunt or broadly pointed, not extending beyond the summit of the fertile lemma; first glume 0.7-1.2 mm long |
......4 Fresh plants light green to blue-green; leaf sheaths usually pilose; ligule of largest culm leaves 3-6× as wide as long; culm blades to 35 cm long, usually pilose on the upper surface |
......4 Fresh plants darker green; leaf sheaths usually glabrous; ligule of largest culm leaves usually > 6× as wide as long; culm blades to 15 cm long, usually glabrate to glabrous on the upper surface |
1 Spikelets 0.9-2.3 mm long. |
........5 Longer blades > 6 cm; if only 6 cm, then sheaths, especially the lower, retrorsely long-pilose ( D. laxiflorum). |
..........6 Spikelets 1.2-1.5 mm long, glabrous |
..........6 Spikelets (1.4-) 1.7-2.3 (-2.8) mm long, pubescent. |
............ 7 Longer blades 10-35 cm long, 2-6 mm wide; sheaths glabrous to variously pilose, but not conspicuously retrorsely long-pilose; nodes variously pubescent to glabrate; spikelets 1.7-2.3 (-2.8) mm long |
............ ..8 Fresh plants light green to blue-green; leaf sheaths usually pilose; ligule of largest culm leaves 3-6× as wide as long; culm blades to 35 cm long, usually pilose on the upper surface |
............ ..8 Fresh plants darker green; leaf sheaths usually glabrous; ligule of largest culm leaves usually > 6× as wide as long; culm blades to 15 cm long, usually glabrate to glabrous on the upper surface |
............ 7 Longer blades 6-18 cm long, 7-12 mm wide; sheaths conspicuously retrorsely long-pilose; nodes bearded with retrorse or spreading hairs; spikelets (1.4-) 1.9-2.3 (-2.5) mm long |
........5 Longer blades 1.5-6 cm; sheaths glabrous or pubescent, but not retrorsely long-pilose. |
............ ....9 Blades 1-3 mm wide, glabrous, eciliate or basally ciliate; spikelets 0.9-1.2 (-1.4) mm long. |
............ ......10 Spikelets pubescent, 1.2-1.4 mm long; blades involute, often falcate, 2.5-6 cm long; [endemic to c. and s. FL scrub] |
............ ......10 Spikelets glabrous, 0.9-1.2 mm long; blades flat, not falcate, 1.5-4 (-5) cm long; [wet sites, VA s. to FL, w. to e. LA] |
............ ....9 Blades 3-8 mm wide; spikelets 1.1-2.1 mm long (or if < 1.5 mm long, then blades either pubescent on one or both surfaces or ciliate to the apex). |
............ ........11 Spikelets pubescent, 1.5-2.1 mm long; blade surfaces glabrous |
............ ........11 Spikelets glabrous, 1.1-1.8 mm long; blade surfaces pubescent or glabrous. |
............ ..........12 Blades glabrous, or sparsely pilose only near the adaxial base; spikelets 1.4-1.8 mm long |
............ ..........12 Blades pilose, at least abaxially; spikelets 1.1-1.6 mm long |
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. |
............ ......10 Spikelets strongly papillose-hispid with spreading hairs 0.5-1 mm long; blades papillose-hispid |
............ ......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 |
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 pseudoligule (see introduction for discussion of the so-called double ligule). |
..2 Culms > 100 cm long; node pubescence densely retrorse; larger blades 12-20 cm long; spikelets acute, 1.9-2.3 mm long, 2× or more as long as wide |
..2 Culms < 100 cm long (rarely longer); node pubescence various; larger blades 3-12 cm long; spikelets rounded to blunt, (1.0-) 1.1-2.0 mm long, less than 2 × as long as wide. |
....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 Spikelets 2.1-2.6 mm long; lower culm blades usually sparsely appressed-pubescent on both surfaces, eciliate or ciliate at the base only |
........5 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 |
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 Basal as well as cauline blades linear, 5-15 cm long,; 1-4 mm wide, 30× or more as long as wide; spikelets 2.8-3.8 (-4.5) mm long |
............ ........11 Blades < 15× as long as wide (if > 15×, then spikelets 1.9-2.5 mm long and sheaths retrorsely pilose in D. laxiflorum). |
............ ..........12 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 |
............ ..........12 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. |
............ ............ 13 Nodes retrorsely bearded; larger vernal leaves 7-15 mm wide. |
............ ............ ..14 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 |
............ ............ ..14 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. |
............ ............ ....15 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 |
............ ............ ....15 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 |
............ ............ 13 Nodes spreading to antrorsely bearded; larger vernal leaves 3-10 mm wide. |
............ ............ ......16 Culm internodes glabrous to sparsely pilose; culm nodes bearded with long retrorse hairs; blade surfaces glabrous to velvety-pubescent |
............ ............ ......16 Culm internodes, at least the lower, strigose, pilose, or villous; culm nodes bearded with ascending or spreading hairs; blade surfaces glabrous or variously hairy. |
............ ............ ........17 Lower nodes bearded with erect-ascending, soft, and long hairs; mid-culm blades usually 20× or more as long as wide. |
............ ............ ..........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 blades 3-6 mm wide, the lower and mid-culm blades of similar width; autumnal 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 blades 2-8 mm wide, the lower usually wider and often shorter than mid-culm blades; autumnal blades involute or flat. |
............ ............ ............ 19 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 |
............ ............ ............ 19 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. |
............ ............ ............ ..20 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 |
............ ............ ............ ..20 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 |
............ ............ ........17 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. |
............ ............ ............ ....21 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. |
............ ............ ............ ......22 Spikelets 2.3-3.0 mm long; ligule < 1 mm long; mid-culm blades 4-8 mm wide |
............ ............ ............ ......22 Spikelets 1.7-2.0 (-2.3) mm long; ligule 1-2.5 mm long; mid-culm leaves 2-5 mm wide |
............ ............ ............ ....21 Blades not noticeably stiff nor longitudinally ribbed, pubescent or strigose underneath, glabrous above or with a few long hairs near the base. |
............ ............ ............ ........23 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 |
............ ............ ............ ........23 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. |
............ ............ ............ ..........24 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 |
............ ............ ............ ..........24 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. |
............ ............ ............ ............ 25 Spikelets 2.1-2.6 mm long; lower culm blades usually sparsely appressed-pubescent on both surfaces, eciliate or ciliate at the base only |
............ ............ ............ ............ 25 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 |
