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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 pilose, at least abaxially; spikelets 1.1-1.6 mm long

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 pilose, at least abaxially; spikelets 1.1-1.6 mm long