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Key to Dichanthelium

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1 Plants densely tufted, often cushion-forming; leaves basally disposed, the blades ascending or spreading-ascending, not forming a distinct rosette of basal leaves shorter than the culm leaves; autumnal culms branching basally or from the lower nodes
1 Plants less densely or sparsely tufted, not cushion-forming; leaves well-distributed on the culm, usually much longer than the short, often broad and spreading basal rosette leaves; autumnal culms usually branching from the mid and upper nodes.
  2 Spikelets 3.3-5.2 mm long
  2 Spikelets 0.8-3.2 mm long.
    3 Spikelets 2.1-3.2 mm long.
      4 Larger culm blades 13-25 mm wide
      4 Larger culm blades < 13 mm wide.
        5 Culm nodes (at least the lower) bearded
        5 Culm nodes not bearded, the lowermost sometimes puberulent or sparsely hairy
    3 Spikelets 0.8-2.0 mm long.
          6 Lower culm internodes variously hairy
          6 Lower culm internodes glabrous

Key to Dichanthelium, Key A: Plants densely tufted, often cushion-forming; leaves basally disposed, the blades ascending or spreading-ascending,
not forming a distinct rosette of basal leaves shorter than the culm leaves; autumnal culms branching basally or from the lower nodes

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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

Key to Dichanthelium, Key B: Spikelets 3.3-5.2 mm long

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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 2.3-4.2 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

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-) 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 (-8) mm long called the pseudoligule (see introduction for discussion of the so-called double ligule).
  2 Culm bases hard, thickened, corm-like; plants producing basal branches instead of rosettes, the branches ultimately producing the largest leaves, 4-13 cm long and 4-11 mm wide; vernal spikelets 2.3-2.7 mm long, 1.2-1.5 mm wide, autumnal spikelets 2.6-2.9 mm long, 1.0-1.1 mm wide; spikelets basally attenuate, the glumes attached 0.2-0.4 mm below expanding base of upper glume and lower lemma; [currently known only from sand ridges in peninsular FL]
  2 Plants without this combination of characters.
    3 Culms > 100 cm long; node pubescence densely retrorse; larger blades 12-20 cm long; spikelets acute; vernal spikelets 1.9-2.3 mm long, slightly < 2× as long as wide; autumnal spikelets 2.2-2.5 mm long, > 2× as long as wide
    3 Culms < 100 cm long (rarely longer); node pubescence various; larger blades 3-12 cm long; spikelets rounded to blunt, < 2× as long as wide.
      4 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
      4 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.
        5 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
        5 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.
          6 Spikelets 2.1-2.6 mm long; lower culm blades usually sparsely appressed-pubescent on both surfaces, eciliate or ciliate at the base only
          6 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.
             7 Culm bases hard, thickened, corm-like; plants producing basal branches instead of rosettes, the branches ultimately producing the largest leaves, 4-13 cm long and 4-11 mm wide; vernal spikelets 2.3-2.7 mm long, 1.2-1.5 mm wide, autumnal spikelets 2.6-2.9 mm long, 1.0-1.1 mm wide; spikelets basally attenuate, the glumes attached 0.2-0.4 mm below expanding base of upper glume and lower lemma; [currently known only from dry sand ridges in peninsular FL]
             7 Plants without this combination of characters.
               8 Ligule 2-5 mm long, ciliate
               8 Ligule < 2 mm long, ciliate or membranous.
                 9 Ligule a stramineous to light brown membrane, with or without terminal cilia; peduncle antrorsely scabrous but not hairy.
                   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
                 9 Ligule entirely of white hairs; peduncle variously hairy or glabrous, but not antrorsely scabrous.
                       12 Culms with a viscid band below the retrorsely bearded nodes; internodes, sheaths, and blades velvety-pubescent
                       12 Culms without a viscid band below the retrorsely, spreading, or antrorsely bearded nodes; internodes and sheaths not velvety-pubescent, blades velvety-pubescent in some.
                          13 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
                          13 Blades < 15× as long as wide (if > 15×, then spikelets 1.9-2.5 mm long and sheaths retrorsely pilose in D. laxiflorum).
                            14 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
                            14 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.
                              15 Nodes retrorsely bearded; larger vernal leaves 7-15 mm wide.
                                16 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
                                16 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.
                                  17 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
                                  17 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
                              15 Nodes spreading to antrorsely bearded; larger vernal leaves 3-10 mm wide.
                                    18 Culm internodes glabrous to sparsely pilose; culm nodes bearded with long retrorse hairs; blade surfaces glabrous to velvety-pubescent
                                    18 Culm internodes, at least the lower, strigose, pilose, or villous; culm nodes bearded with ascending or spreading hairs; blade surfaces glabrous or variously hairy.
                                       19 Lower nodes bearded with erect-ascending, soft, and long hairs; mid-culm blades usually 20× or more as long as wide.
                                         20 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
                                         20 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.
                                           21 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
                                           21 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.
                                             22 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
                                             22 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
                                       19 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.
                                               23 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.
                                                 24 Spikelets 2.3-3.0 mm long; ligule < 1 mm long; mid-culm blades 4-8 mm wide
                                                 24 Spikelets 1.7-2.0 (-2.3) mm long; ligule 1-2.5 mm long; mid-culm leaves 2-5 mm wide
                                               23 Blades not noticeably stiff nor longitudinally ribbed, pubescent or strigose underneath, glabrous above or with a few long hairs near the base.
                                                    25 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
                                                    25 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.
                                                      26 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
                                                      26 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.
                                                        27 Spikelets 2.1-2.6 mm long; lower culm blades usually sparsely appressed-pubescent on both surfaces, eciliate or ciliate at the base only
                                                        27 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

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 below 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, 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, (2.1-) 2.2-2.6 mm long; fertile lemma and palea papillose or smooth; first glume usually broadened above base, rounded or broadly tapered distally; glume bases often reddish-purple.
                                                        27 Culm leaves 2-5 mm wide; fertile lemma and palea smooth, shiny
                                                        27 Culm leaves 4-12 mm wide; fertile lemma and palea papillose-roughened
                                                      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 glume usually tapered from near base to apex; glume bases various
                                               23 Culm internodes crisp-puberulent (sparsely so in D. webberianum); sheaths puberulent or glabrous.
                                                          28 Spikelets elliptic, sub-acute to pointed, greenish or faintly purple-tinged basally
                                                          28 Spikelets strongly plano-convex when viewed laterally, obpyriform when viewed dorsally, broadly rounded, usually markedly reddish-purple basally.
                                                            29 Fertile lemma and palea papillose; spikelets 2.2-2.6 mm long; lower culm blades 6-12 mm wide, glabrous
                                                            29 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)

Key to Dichanthelium, Key F: Spikelets 0.8-2.0 mm long, lower culm internodes variously hairy

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1 Longer hairs of ligule 2-5 mm long.
  2 Ligule with a distinct ring of short hairs in front of the long hairs.
    3 Peduncle, panicle axis, and sheaths puberulent with hairs 0.1 mm long; larger blades 3-6 cm long, 3-5 mm wide; spikelets 1.3-1.7 mm long
    3 Peduncle, panicle axis, and sheaths pubescent with hairs more than 0.1 mm long; larger blades 12-20 cm long, 7-9 mm wide; spikelets 1.9-2.3 mm long
  2 Ligule without a distinct ring of short hairs in front of the long hairs.
      4 Culms > 100 cm long; node pubescence densely retrorse; larger blades 12-20 cm long; vernal spikelets 1.9-2.3 mm long, nearly 2× as long as wide; autumnal spikelets 2.2-2.5 mm long, > 2× as long as wide
      4 Culms < 100 cm long (-rarely longer); node pubescence various; larger blades 3-12 cm long; spikelets (1.0-) 1.1-2.0 mm long, less than 2 × as long as wide, rounded to blunt.
        5 Blades of mid-culm leaves lanceolate, thin or firm but not stiff, length and width various, less than 15× as long as wide
        5 Blades of mid-culm leaves linear or narrowly lanceolate, stiff, acuminate, often involute, 4-10 cm long, 2-5 mm wide, about 15-20× as long as wide
1 Longer hairs of ligule < 2 mm long.
          6 Culm leaves basally crowded, ascending, usually matted or cushion-forming, larger than the mid and upper culm blades.
             7 Sheaths conspicuously retrorsely long-pilose; longer blades 6-18 cm long and 7-12 mm wide; spikelets (1.4-) 1.9-2.3 (-2.5) mm long
             7 Sheaths variously pubescent or glabrous, but not conspicuously retrorsely long-pilose; longer blades 2-6 cm long and 1-8 mm wide; spikelets 0.9-2.1 mm long.
               8 Leaf blades 1-4 mm wide, glabrous, the margins eciliate or basally ciliate; spikelets 0.9-1.5 mm long, glabrous; autumnal form branched from lower and mid nodes as well as from basal nodes.
                 9 Leaf blades 1.5-4 (-5) cm long; spikelets 0.9-1.2 (-1.4) mm long
                 9 Leaf blades 4-12 (-20) cm long, some at least 7 cm long; spikelets 1.2-1.5 mm long
               8 Leaf blades 2-10 mm wide, pubescent or glabrous, the margins coarsely papillose-ciliate throughout; spikelets 1.1-2.1 mm long, glabrous or pubescent; autumnal form branched from basal nodes only.
                   10 Spikelets pubescent, 1.5-2.1 mm long; blade surfaces glabrous
                   10 Spikelets glabrous, 1.1-1.8 mm long; blade surfaces pubescent or glabrous.
                     11 Leaf blades glabrous, or sparsely pilose only near the adaxial base; spikelets 1.4-2.1 mm long
                     11 Leaf blades pilose, at least abaxially; spikelets 1.1-1.6 mm long
          6 Culm leaves not basally crowded, the lowest leaves spreading and rosette-forming, usually smaller than the culm leaves.
                       12 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
                       12 Blades similar or more often decreasing in size upwards on culm; if 15 × or more as long as wide, then larger blades 4-10 cm long and 2-5 mm wide, 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 equaling fertile lemma.
                          13 Blades of mid-culm leaves linear or narrowly lanceolate, stiff, acuminate, often involute, 4-10 cm long, 2-5 mm wide, about 15-20× as long as wide.
                            14 Ligule less than 1 mm long; nodes glabrous to sparsely pubescent, not bearded; blades glabrous (lowest sometimes sparsely pilose); autumnal blades involute
                            14 Ligule (1-) 1.5-2 (-2.5) mm long; nodes bearded with spreading-ascending hairs; blades moderately hirsute; autumnal blades flat
                          13 Blades of mid-culm leaves lanceolate to lance-elliptic, thin or firm but not stiff, length and width various, < 15× as long as wide.
                              15 Internodes crisp-puberulent.
                                16 Ligule 0.7-1.5 mm long; first glume acute; spikelets elliptic when viewed dorsally, biconvex or elliptic when viewed laterally, not strongly nerved
                                16 Ligule < 0.5 mm long; first glume obtuse to truncate; spikelets obovate when viewed dorsally, plano-convex when viewed laterally, strongly nerved.
                                  17 Spikelets (1.8-) 1.9-2.2 (-2.5) mm long; first glume 0.8-1.2 mm long; lower culm blades 2-8 mm wide
                                  17 Spikelets 1.5-1.8 mm long; first glume 0.5-0.8 mm long; lower culm blades 2-5 mm wide
                              15 Internodes variously hairy but not crisp-puberulent.
                                    18 Culms (55-) 70-140 cm long; nodes retrorsely bearded; vernal cauline leaves 6-15; blades 6-15 cm long, 8-13 mm wide, glabrous
                                    18 Culms < 60 cm long; nodes not retrorsely bearded; vernal cauline leaves 2-7; blades to 14 cm long and 17 mm wide, glabrous or pubescent.
                                       19 Internodes (sparsely-) moderately to densely pubescent to pilose; ligule 1-5 mm long; blade margins either weakly ciliate, papillose-ciliate basally only, or eciliate, lacking a white-beige cartilaginous edge 0.2 mm wide.
                                         20 Larger mid-culm blades 4-7 cm long, 4-7 mm wide, glabrous to sparsely pubescent adaxially; ligule 1-5 mm long; spikelets 1.1-1.5 mm long
                                         20 Larger mid-culm blades 3-6 cm long, 3-5 mm wide, long-pilose adaxially; ligule often with a ring of hairs < 1 mm and scattered longer hairs to 4 mm; spikelets 1.3-1.7 mm long
                                       19 Internodes sparsely pilose; ligule < 1 mm long; blade margins various.
                                           21 Blades 5-14 cm by 5-17 mm, basally truncate to cordate, margins only ciliate basally if at all, without a white-beige margin up to 0.2 mm wide
                                           21 Blades 1.5-6 (8) cm by 2-8 mm, basally narrowed to rounded, blade margins either coarsely papillose-ciliate throughout or glabrous with a white-beige cartilaginous edge about 0.2 mm wide.
                                             22 Blades with white-beige cartilaginous margins 0.2 mm wide; spikelets 1.4-1.7 mm long; autumnal form branching from middle and upper nodes
                                             22 Blade margins coarsely papillose-ciliate throughout; spikelets 1.1-2.1 mm long; autumnal form branching from the base.
                                               23 Spikelets pubescent, 1.5-2.1 mm long; blade surfaces glabrous
                                               23 Spikelets glabrous, 1.1-1.8 mm long; blade surfaces pubescent or glabrous.
                                                 24 Blades glabrous, or sparsely pilose only near the adaxial base; spikelets 1.4-1.8 mm long
                                                 24 Blades pilose; spikelets 1.1-1.6 mm long

Key to Dichanthelium, Key G: Spikelets 0.8-2.0 mm long, lower culm internodes glabrous

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1 Ligule 1-5 mm long.
  2 Ligule (1.5-) 2-5 mm long; sheaths glabrous to variously pubescent; internodes glabrous or pubescent; nodes glabrous, or bearded with ascending, spreading, or tangled hairs; leaves 3-10 cm long, 3-10 mm wide; spikelets 0.8-1.9 mm long
  2 Ligule 1-2 mm long; sheaths sparsely to moderately spreading short-pilose; internodes glabrous; nodes retrorsely bearded; leaves 1-4 cm long, 2-5 mm wide; spikelets 1.2-1.4 mm long
1 Ligule < 1 mm long.
    3 Basal leaves rosette-forming, usually much smaller than the culm leaves, not matted or cushion-forming; culms branching at the mid and upper nodes in age.
      4 Blades of mid-culm leaves typically long and acuminate, linear or narrowly lanceolate, usually 10-20× as long as wide, only 2-5 mm wide when < 8 cm long.
        5 Vernal leaf blades 9-20 cm long, the larger usually 5-8 mm wide, becoming longer upwards on the culm, (weakly-) strongly scabrous on the adaxial surface; spikelets sparsely pubescent to glabrous
        5 Vernal leaf blades to 11(14) cm long, those on the upper culm smaller or similar in size to those below, the adaxial surface not scabrous except sometimes on the margins (or scabrous in D. neuranthum with leaves no more than 5 mm wide and spikelets moderately glandular papillose-pubescent).
          6 Spikelets (glandular-) papillose-pubescent; blades 1-3 (-5) mm wide; first glume 0.8-1.0 mm long; culms to 4 dm tall
          6 Spikelets glabrous; blades 3-8 mm wide; first glume 0.3-1.1 mm long; culms to 10 dm tall.
             7 Leaves 3-8 mm wide; panicle (8-) 20-40 mm wide; first glume 0.6-1.1 mm long, blunt to acute
             7 Leaves 3-5.5 mm wide; panicle 2-5 mm wide; first glume 0.3-0.4 mm long, truncate to obtuse
      4 Blades of mid-culm leaves lanceolate, mostly 10× or less as long as wide, usually 7 mm or more wide when as much as 8 cm long.
               8 Spikelets elliptic, oblong, or obovate; lower culm blades 3-12 (-15) mm wide, thin, tapered to the base; plants often freely branching in age, becoming top-heavy with a mass of fascicled, reduced leafy branches and inflorescences
               8 Spikelets broadly elliptic to suborbicular; lower culm blades 6-30 mm wide, broad and cordate to subcordate at the base; plants sparingly branched in age, not becoming top-heavy with fascicled, reduced leafy branches and inflorescences.
                 9 Leaf blades not noticeably thick; ligules ciliate, to 0.8 mm long; spikelets 1.8-2.6 mm long, elliptic, obtuse to subacute; first glumes 0.5-1.0 mm long
                 9 Leaf blades thickish; ligule obsolete or with cilia < 0.8 mm long; spikelets 0.9-1.9 mm long, obovoid to spherical, rounded; first glumes 0.2-0.8 mm long.
                   10 Spikelets 0.9-1.2 mm long; longer blades 6-8 cm long, erect to erect-ascending
                   10 Spikelets 1.2-1.9 mm long; longer blades 8-20 cm long, ascending or the uppermost erect.
                     11 Mid-culm blades to 25 cm long, 14-30 mm wide, the uppermost 10-15+ cm long; vernal panicles to 20 cm long, often less than half as wide as long; spikelets 1.3-1.6 (-1.7)
                     11 Mid-culm blades to 10 cm long, 5-11 (-14) mm wide, the uppermost 3-9 cm long; vernal panicles to 14 cm long, usually more than half as wide as long; spikelets (1.4-) 1.5-1.8 mm long
    3 Basal leaves similar to or larger than the mid and upper culm leaves, often matted or cushion-forming; culms branching at the base (also at mid and upper nodes in D. chamaelonche vars. and D. dichotomum var. glabrifolium).
                       12 Longer blades > 6 cm; if only 6 cm, then sheaths retrorsely long-pilose (D. laxiflorum).
                          13 Spikelets 1.2-1.5 mm long, glabrous
                          13 Spikelets 1.7-2.3 (-2.8) mm long, pubescent.
                            14 Longer blades 6-18 cm long by 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
                            14 Longer blades 10-35 cm long by 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.
                              15 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
                              15 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
                       12 Longer blades 1.5-6 cm; sheaths glabrous or pubescent, but not retrorsely long-pilose.
                                16 Blades 1-3 mm wide, glabrous, eciliate or basally ciliate; spikelets 0.9-1.4 mm long.
                                  17 Spikelets pubescent, 1.2-1.4 mm long; blades involute, often falcate, 2.5-6 cm long; [endemic to c. and s. FL scrub]
                                  17 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]
                                16 Blades 3-8 mm wide; spikelets 1.1-2.1 mm long (if < 1.5 mm, then blades either pubescent on one or both surfaces or ciliate to the apex).
                                    18 Spikelets pubescent, 1.5-2.1 mm long; blade surfaces glabrous
                                    18 Spikelets glabrous, 1.1-1.8 mm long; blade surfaces pubescent or glabrous.
                                       19 Blades glabrous, or sparsely pilose only near the adaxial base; spikelets 1.4-2.1 mm long
                                       19 Blades pilose, at least abaxially; spikelets 1.1-1.6 mm long

Key to Dichanthelium, Key to the Dichanthelium acuminatum group

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1 Internodes glabrous (sometimes lowest internodes sparsely to moderately pubescent).
  2 Ligule 1-2 mm long; sheaths sparsely to moderately spreading short-pilose; nodes retrorsely bearded; leaves 1-4 cm long, 2-5 mm wide; spikelets 1.2-1.4 mm long
  2 Ligule (1.5-) 2-5 mm long; sheaths glabrous to variously pubescent, but not spreading short-pilose; nodes glabrous or pubescent, but not bearded; leaves 4-11 cm long, 4-8 mm wide.
    3 Leaf blade basal cilia usually conspicuous; larger vernal blades 6-10 cm by 6-10 mm; internodes, especially lower, sometimes pilose; spikelets obovoid; plant often yellowish-green (orange-brown in age)
    3 Leaf blade basal cilia usually inconspicuous or absent; larger vernal blades 2.5-10 cm long, 2-9 mm wide; all internodes glabrous (rarely the lowest sparsely pilose); spikelets ellipsoid; plant often green to purplish.
      4 Spikelets (0.9-) 1.1-1.5 mm long, moderately densely to densely puberulent, most hairs < 0.1 mm long; panicles 3-8 cm long, usually more than ½ as wide as long; larger blades 2.5-8 cm long
      4 Spikelets (1.3-) 1.4-1.9 mm long, (glabrous-) sparsely to moderately pubescent, most hairs > 0.1 mm long; panicles 4-12 cm long, usually less than ½ as wide as long; larger blades 7-10 cm long
1 Internodes variously pubescent.
        5 Peduncle, panicle axis, and/or sheaths of vernal culms puberulent with hairs 0.1 mm long, sometimes also pubescent with longer hairs, but never grayish-villous; larger leaf blades 2-7 cm long, 2-7 mm wide.
          6 Spikelets 0.8-1.1 mm long; mid-culm leaf blades 2-4.5 cm long, 2-5 mm wide; sheaths sparsely puberulent to glabrous, lacking papillose-based longer hairs
          6 Spikelets 1.1-1.7 mm long; mid-culm leaf blades generally 3-7 cm long and 3-7 mm wide; sheaths with some papillose-based hairs 2 mm or more long.
             7 Larger mid-culm leaf blades 4-7 cm long, 4-7 mm wide, glabrous to sparsely pubescent adaxially; ligule 1-5 mm long; spikelets 1.1-1.5 mm long
             7 Larger mid-culm leaf blades 3-6 cm long, 3-5 mm wide, long-pilose adaxially; ligule often with a ring of hairs < 1 mm and scattered longer hairs to 4 mm; spikelets 1.3-1.7 mm long
        5 Peduncle, panicle axis, and sheaths of vernal culms glabrous, or pilose, or grayish-villous with some shorter hairs 0.2-0.5 mm long, but not puberulent with hairs 0.1 mm long; larger blades 4-20 cm long, 4-12 mm wide.
               8 Culms > 100 cm long; node pubescence densely retrorse; larger blades 12-20 cm long; vernal spikelets 1.9-2.3 mm long, nearly 2× as long as wide; autumnal spikelets 2.2-2.5 mm long, > 2× as long as wide
               8 Culms < 100 cm long (-rarely longer); node pubescence various; larger blades 4-12 cm long, < 15 × as long as wide; spikelets (1.0-) 1.1-2.0 mm long, less than 2× as long as wide, rounded to blunt.
                 9 Sheaths and internodes of vernal culms gray-villous with a dense, tangled, or matted mixture of slender hairs 2-4 mm long, variously ascending, spreading, and retrorse, papillose or non-papillose, often with shorter hairs beneath; leaf blades velvety-pubescent on abaxial surface, the margins ciliate (or appearing ciliate) for half or more their length.
                   10 Plants drying light green to yellow-green; culms usually < 60 cm long; lower internodes rarely more than 1.3 mm in diameter; panicles usually < 8 cm long; primary branching at most nodes before maturation of vernal panicle, longer branches often exceeding the culm
                   10 Plants drying olive-green, sometimes purplish; culms usually > 60 cm long; lower internodes usually > 2 mm in diameter; panicles usually 9-11 cm long; primary branching sparingly from middle nodes after maturation of vernal panicle, longer branches not exceeding culm
                 9 Sheaths and internodes of vernal culms puberulent, pubescent or papillose-pilose to hispid with ascending straight hairs, but never grayish-villous; leaf blades glabrous to variously pilose abaxially, but not velvety-pubescent, the margins eciliate or ciliate only below the middle.
                     11 Spikelets 0.8-1.1 mm long; blades 2-4.5 cm long, 2-5 mm wide
                     11 Spikelets 1.1-2.0 mm long; blades 3-12 cm long, 3-12 mm wide.
                       12 Peduncle, panicle axis, and often middle and upper internodes glabrous; sheaths lacking hairs or papillae, at least near mid-length
                       12 Peduncle, panicle axis, and internodes puberulent, pubescent, or pilose; sheaths papillose-pilose to hispid.
                          13 Leaf blades 5-12 cm long, 6-12 mm wide; spikelets 1.5-2.0 mm long; peduncle, panicle axis, and sheaths variously pilose, but lacking puberulent hairs 0.1 mm long
                          13 Leaf blades 3-7 cm long, 3-7 mm wide; spikelets 1.1-1.7 mm long; puberulent hairs 0.1 mm long often present on peduncle, panicle axis, or sheaths.
                            14 Larger mid-culm leaf blades 4-7 cm long, 4-7 mm wide, glabrous to sparsely pubescent adaxially; ligule 1-5 mm long, the hairs of one series; spikelets 1.1-1.5 mm long
                            14 Larger mid-culm leaf blades 3-6 cm long, 3-5 mm wide, long-pilose adaxially; ligule often with a short series of hairs <1 mm long in front of a series with hairs to 4 mm long; spikelets 1.3-1.7 mm long

Key to Dichanthelium, Key to the Dichanthelium dichotomum group

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1 Lower cauline nodes bearded, the hairs usually retrorse.
  2 Spikelets glabrous.
    3 Ligule an eciliate membrane; fertile lemma and palea densely papillose at 20×; leaves 3.5-7 cm long by 3-6 mm wide; culms weak, usually sprawling over other vegetation
    3 Ligule ciliate; fertile lemma and palea smooth, with few or no papillae; leaves either 1.5-4 (-5) cm long by 1-5 mm wide, or 5-12 cm long by 3-15 mm wide.
      4 Spikelets 0.9-1.4 mm long; vernal cauline blades 1.5-4 (-5) cm long and 1-5 mm wide; internodes or sheaths glabrous or pubescent.
        5 Spikelets 0.9-1.2 (-1.4) mm long; sheaths glabrous; vernal cauline blades 1-2 (-3) mm wide; ligule < 1 mm long; node beard hairs erect and often only partially encircling the node; internodes glabrous or puberulent
        5 Spikelets 1.2-1.4 mm long; sheaths spreading-pilose; vernal cauline blades 2-5 mm wide; ligule 1-2 mm long; node beard hairs usually spreading or reflexed; internodes glabrous
      4 Spikelets 1.4-2.3 mm long; vernal cauline blades 5-12 cm long and 3-15 mm wide; internodes and sheaths glabrous.
          6 Spikelets 1.8-2.3 mm long; first glume 0.6-1.1 mm long; fertile lemma 0.8-1.0 mm wide; widest vernal blades 3-8 (-10) mm wide; nodes, often only the lower, usually sparsely to moderately bearded with retrorse hairs
          6 Spikelets 1.4-1.9 mm long; first glume 0.3-0.6 (-0.7) mm long; fertile lemma 0.6-0.8 mm wide; widest vernal blades 7-15 mm wide; usually all nodes densely bearded with retrorse hairs
  2 Spikelets pubescent.
             7 Spikelets 1.2-1.4 mm long; sheaths spreading-pilose; vernal cauline blades 1-4 cm long and 2-5 mm wide; ligule 1-2 mm long
             7 Spikelets 1.4-2.8 mm long; sheaths glabrous to pilose; vernal cauline blades 5-15 cm long and 5-15 mm wide; ligule ≤ 1 mm long.
               8 Culms(55-) 70-140 cm long; lowest internodes moderately to densely villous; vernal cauline leaves 6-15; blades glabrous except for basal cilia; spikelets 1.8-2.2 mm long, obovoid to broadly ellipsoid, rounded to blunt
               8 Culms 30-110 cm long; lowest internodes glabrous to sparsely hairy; vernal cauline leaves 3-7; spikelets 1.4-2.8 mm long, elliptic to lance-ovate, blunt to acute.
                 9 Usually all culm nodes bearded; internodes glabrous, or middle and upper internodes and peduncle sparsely to moderately spreading short-hairy, sometimes also glandular; upper as well as lower vernal sheaths and both surfaces of cauline blades pubescent, often densely so; spikelets (1.5-) 1.8-2.2 mm long; [of dry rocky or sandy basic soil and barrens]
                 9 Often only lower culm nodes bearded; internodes glabrous; at least middle and upper cauline blades glabrous; spikelets 1.4-2.8 mm long; [mostly of wet acid soils and mesic to dry woodlands].
                   10 Spikelets (2.0-) 2.2-2.8 mm long; first glume 0.5-1.3 mm long; fertile lemma 1.8-2.3 mm long; lowest vernal cauline blades pubescent at least abaxially
                   10 Spikelets 1.4-2.2 mm long; first glume 0.3-0.9 mm long; fertile lemma 1.4-1.7 mm long; lowest vernal cauline blades glabrous.
                     11 Spikelets 1.7-2.2 mm long; first glume 0.6-0.9 mm long; fertile lemma 0.7-1.0 mm wide
                     11 Spikelets 1.4-1.9 mm long; first glume 0.3-0.6 (-0.8) mm long; fertile lemma 0.6-0.8 mm wide
1 Lower cauline nodes glabrous or puberulent, but not bearded.
                       12 Spikelets pubescent.
                          13 Spikelets (1.5-) 1.7-2.7 mm long, if shorter than 1.8 mm then fertile lemma and palea densely papillose; culms soon sprawling.
                            14 Spikelets (1.5-) 1.7-2.3 mm long, glabrous (rarely pubescent); first glume 0.7-1.1 mm long; fertile lemma and palea densely papillose at 20×
                            14 Spikelets 2.2-2.7 mm long, pubescent; first glume 1.0-1.4 mm long; fertile lemma and palea smooth or with a few weak papillae at 20×
                          13 Spikelets 1.2-1.7 mm long; fertile lemma and palea smooth; culms erect.
                              15 Leaf blades involute and often falcate, 3-6 cm long, about 1.5 mm wide when flattened, 20-50× as long as wide; lower internodes often strigose; spikelets 1.2-1.4 mm long; culms 5-20 cm long; [endemic to c. and s. FL scrub]
                              15 Leaf blades neither involute (except apically) nor falcate, 1-7 cm long, 1.5-7 mm wide, about 10× as long as wide; lower internodes glabrous or sparsely pilose, but not strigose; spikelets 1.1-1.7 mm long; culms 15-60 cm long; [wet sites, collectively widespread in coastal plain from NJ to TX and sparsely inland]
                                16 Leaf blades (3-) 4-6 (-9) per culm, pliable, 1-3.5 (-5) cm long, 1.5-4 mm wide, the margins flat and sharp-edged, gray-green to white-beige, 0.1 mm wide or less; spikelets 1.2-1.5 mm long, pubescent or glabrous; culms to 40 cm long
                                16 Leaf blades 3-4 per culm, firm, 2-6 (-8) cm long, 2-6 (-8) mm wide, at least one margin cartilaginously thickened, the edge usually rounded, white-beige to green-stramineous, 0.1-0.2 mm wide; spikelets (1.1-) 1.3-1.7 mm long, pubescent; culms to 60 cm long
                       12 Spikelets glabrous.
                                  17 Cauline leaves mostly basally disposed, strongly ascending, much larger than the 2-3 remote middle and upper cauline leaves of fertile culms; spikelets 2.4-2.9 mm long; culms branch from basal and lower nodes, but are not known to produce autumnal inflorescences; [Wet pine savannas and seepages; endemic to Gulf Coastal Plain]
                                  17 Cauline leaves well-distributed along the culm, > 3, gradually reduced upward and often spreading; spikelets 0.9-2.6 mm long; culms produce autumnal inflorescences from lower, middle, and/or upper nodes, if from lower only, then spikelets only 0.9-1.2 mm long; [collectively widespread, habitats various].
                                    18 Fertile lemma and palea densely papillose; ligule usually ciliate, rarely an eciliate membrane 0.1-0.3 mm long; culms weak, soon sprawling over vegetation
                                    18 Fertile lemma and palea smooth, with few or no papillae; ligule always ciliate.
                                       19 Spikelets 0.9-1.5 mm long; vernal blades 1-4 mm wide; culms stiffer, erect to ascending.
                                         20 Spikelets 0.9-1.2 (-1.4) mm long; blades 1.5-4 (-5) cm long, 1-2.5 (-3) mm wide, mostly 15-20 times as long as wide; autumnal plants cushion-forming
                                         20 Spikelets 1.2-1.5 mm long; blades 1-12 (-20) cm long; autumnal plants not cushion-forming.
                                           21 Leaf blades 1-3 (-5) cm long, 1.5-3 (-4) mm wide, about 10 times as long as wide; autumnal plants sparsely tufted
                                           21 Leaf blades 4-12 (-20) cm long (the longer at least 7 cm), 2-4 mm wide, 20-30 (-50) times as long as wide
                                       19 Spikelets 1.4-2.6 mm long; vernal blades 3-15 mm wide (if spikelets < 1.6 mm long and vernal blades < 5 mm wide, then larger blades > 5 cm long in D. caerulescens).
                                             22 Widest vernal cauline blades 7-15 mm wide; upper sheaths often glutinous-warty; spikelets 2.1-2.6 mm long, some or most acute to beaked, second glume and sterile lemma extending 0.3-0.5 mm beyond fertile lemma in at least some spikelets
                                             22 Widest vernal cauline blades 3-10 mm wide; upper sheaths not glutinous-warty; spikelets 1.4-2.3 mm long, blunt to subacute, second glume and sterile lemma often equal to or shorter than fertile lemma, or extending < 0.3 mm beyond it.
                                               23 Spikelets 1.4-1.8 mm long; first glume 0.3-0.8 mm long; fertile lemma 1.3-1.5 mm long; mature vernal panicles usually short-exserted with ascending branches; fresh foliage bluish-glaucous
                                               23 Spikelets 1.7-2.3 mm long; first glume 0.6-1.1 mm long; fertile lemma 1.6-1.9 mm long; mature vernal panicles exserted with spreading branches; fresh foliage not bluish-glaucous.
                                                 24 Vernal panicle smooth to weakly scabrous, the scabrousness usually confined to the pedicels; vernal cauline blades spreading to deflexed, flexuous; autumnal form densely bushy-fascicled, essentially forming one large mass of clustered leaves [of wet-mesic to dry woods and thickets]
                                                 24 Vernal panicle moderately to densely scabrous, increasingly so from rachis to branches to pedicels; vernal cauline blades stiffly erect; autumnal fascicles forming isolated clusters of leaves [of wet pine savannas and open swamps]