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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 |
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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 |
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 |
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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 |