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

Poaceae

Dichanthelium

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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

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)