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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; spikelets 1.9-2.3 mm long, 2 × or more as long as wide, acute |
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 |
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 |
Show caption*© Janet Wright, some rights reserved (CC BY-NC), uploaded by Janet Wright 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, 15-20 × as long as wide; spikelets 1.9-2.3 mm long, 2× or more as long as wide, acute |
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 |
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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 |