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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 |
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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 |