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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
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
3 Spikelets 2.8-3.8 (-4.5) mm long, the second glume and sterilelemma 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 sterilelemma 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
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
2Ligule without a distinct ring of short hairs in front of the long hairs.
4 Culms > 100 cm long; nodepubescence 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); nodepubescence 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
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
6Culm 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; bladeadaxial surface (weakly-) strongly scabrous; sheaths glabrous; second glume and sterilelemma 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); bladeadaxial surface smooth to moderately scabrous; sheaths glabrous or pilose; second glume and sterilelemma 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.
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
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
2Ligule 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
3Basal 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.
5Vernal 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
5Vernal 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 glandularpapillose-pubescent).
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; liguleobsolete 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
3Basal 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).
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
3Liguleciliate; fertile lemma and palea smooth, with few or no papillae; leaves either 1.5-4 (-5) cm long by 1-5 mm wide, or 5-12 cm long by 3-15 mm wide.
4 Spikelets 0.9-1.4 mm long; vernalcauline blades 1.5-4 (-5) cm long and 1-5 mm wide; internodes or sheaths glabrous or pubescent.
4 Spikelets 1.4-2.3 mm long; vernalcauline blades 5-12 cm long and 3-15 mm wide; internodes and sheaths glabrous.
6 Spikelets 1.8-2.3 mm long; first glume 0.6-1.1 mm long; fertile lemma 0.8-1.0 mm wide; widest vernal blades 3-8 (-10) mm wide; nodes, often only the lower, usually sparsely to moderately bearded with retrorse hairs
6 Spikelets 1.4-1.9 mm long; first glume 0.3-0.6 (-0.7) mm long; fertile lemma 0.6-0.8 mm wide; widest vernal blades 7-15 mm wide; usually all nodes densely bearded with retrorse hairs
8 Culms(55-) 70-140 cm long; lowest internodes moderately to densely villous; vernalcauline leaves 6-15; blades glabrous except for basalcilia; spikelets 1.8-2.2 mm long, obovoid to broadly ellipsoid, rounded to blunt
8 Culms 30-110 cm long; lowest internodes glabrous to sparsely hairy; vernalcauline leaves 3-7; spikelets 1.4-2.8 mm long, elliptic to lance-ovate, blunt to acute.
9 Usually all culm nodes bearded; internodes glabrous, or middle and upper internodes and peduncle sparsely to moderately spreading short-hairy, sometimes also glandular; upper as well as lower vernal sheaths and both surfaces of cauline blades pubescent, often densely so; spikelets (1.5-) 1.8-2.2 mm long; [of dry rocky or sandy basic soil and barrens]
9 Often only lower culm nodes bearded; internodes glabrous; at least middle and upper cauline blades glabrous; spikelets 1.4-2.8 mm long; [mostly of wet acid soils and mesic to dry woodlands].
10 Spikelets (2.0-) 2.2-2.8 mm long; first glume 0.5-1.3 mm long; fertile lemma 1.8-2.3 mm long; lowest vernalcauline blades pubescent at least abaxially
13 Spikelets 1.2-1.7 mm long; fertile lemma and palea smooth; culms erect.
15 Leaf blades involute and often falcate, 3-6 cm long, about 1.5 mm wide when flattened, 20-50× as long as wide; lower internodes often strigose; spikelets 1.2-1.4 mm long; culms 5-20 cm long; [endemic to c. and s. FL scrub]
15 Leaf blades neither involute (except apically) nor falcate, 1-7 cm long, 1.5-7 mm wide, about 10× as long as wide; lower internodes glabrous or sparsely pilose, but not strigose; spikelets 1.1-1.7 mm long; culms 15-60 cm long; [wet sites, collectively widespread in coastal plain from NJ to TX and sparsely inland]
16 Leaf blades (3-) 4-6 (-9) per culm, pliable, 1-3.5 (-5) cm long, 1.5-4 mm wide, the margins flat and sharp-edged, gray-green to white-beige, 0.1 mm wide or less; spikelets 1.2-1.5 mm long, pubescent or glabrous; culms to 40 cm long
16 Leaf blades 3-4 per culm, firm, 2-6 (-8) cm long, 2-6 (-8) mm wide, at least one margin cartilaginously thickened, the edge usually rounded, white-beige to green-stramineous, 0.1-0.2 mm wide; spikelets (1.1-) 1.3-1.7 mm long, pubescent; culms to 60 cm long
17Cauline leaves mostly basally disposed, strongly ascending, much larger than the 2-3 remote middle and upper cauline leaves of fertile culms; spikelets 2.4-2.9 mm long; culms branch from basal and lower nodes, but are not known to produce autumnal inflorescences; [Wet pine savannas and seepages; endemic to Gulf Coastal Plain]
17Cauline leaves well-distributed along the culm, > 3, gradually reduced upward and often spreading; spikelets 0.9-2.6 mm long; culms produce autumnal inflorescences from lower, middle, and/or upper nodes, if from lower only, then spikelets only 0.9-1.2 mm long; [collectively widespread, habitats various].
19 Spikelets 0.9-1.5 mm long; vernal blades 1-4 mm wide; culms stiffer, erect to ascending.
20 Spikelets 0.9-1.2 (-1.4) mm long; blades 1.5-4 (-5) cm long, 1-2.5 (-3) mm wide, mostly 15-20 times as long as wide; autumnal plants cushion-forming
19 Spikelets 1.4-2.6 mm long; vernal blades 3-15 mm wide (if spikelets < 1.6 mm long and vernal blades < 5 mm wide, then larger blades > 5 cm long in D. caerulescens).
22 Widest vernalcauline blades 7-15 mm wide; upper sheaths often glutinous-warty; spikelets 2.1-2.6 mm long, some or most acute to beaked, second glume and sterilelemma extending 0.3-0.5 mm beyond fertile lemma in at least some spikelets
22 Widest vernalcauline blades 3-10 mm wide; upper sheaths not glutinous-warty; spikelets 1.4-2.3 mm long, blunt to subacute, second glume and sterilelemma often equal to or shorter than fertile lemma, or extending < 0.3 mm beyond it.
23 Spikelets 1.4-1.8 mm long; first glume 0.3-0.8 mm long; fertile lemma 1.3-1.5 mm long; mature vernal panicles usually short-exserted with ascending branches; fresh foliage bluish-glaucous
23 Spikelets 1.7-2.3 mm long; first glume 0.6-1.1 mm long; fertile lemma 1.6-1.9 mm long; mature vernal panicles exserted with spreading branches; fresh foliage not bluish-glaucous.
24Vernalpanicle moderately to densely scabrous, increasingly so from rachis to branches to pedicels; vernalcauline blades stiffly erect; autumnal fascicles forming isolated clusters of leaves [of wet pine savannas and open swamps]