Part 7 - UNC Herbarium

POACEAE 868
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).
10 Longer blades > 6 cm; if only 6 cm, then sheaths retrorsely long-pilose (D. laxiflorum).
11 Spikelets 1.2-1.5 mm long, glabrous ...........................................................[D. dichotomum var. glabrifolium]
11 Spikelets 1.7-2.3 (-2.8) mm long, pubescent.
12 Longer blades 6-18 cm long by 7-12 mm wide; sheaths conspicuously retrorsely long-pilose; nodes
bearded with retrorse or spreading hairs; spikelets 1.9-2.3 mm long ................................... D. laxiflorum
12 Longer blades 10-35 cm long by 2-4 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 ................................................................................................................................... D. linearifolium
10 Longer blades 1.5-6 cm; sheaths glabrous or pubescent, but not retrorsely long-pilose.
13 Blades 1-3 mm wide, glabrous, eciliate or basally ciliate; spikelets 0.9-1.4 mm long.
14 Spikelets pubescent, 1.2-1.4 mm long; blades involute, often falcate, 2.5-6 cm long .................................
.................................................................................................................... [D. chamaelonche ssp. breve]
14 Spikelets glabrous, 0.9-1.2 mm long; blades flat, not falcate, 1.5-4 (-5) cm long .......................................
........................................................................................................ D. chamaelonche ssp. chamaelonche
13 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).
15 Spikelets pubescent, 1.5-2.1 mm long; blade surfaces glabrous............. D. strigosum var. leucoblepharis
15 Spikelets glabrous, 1.1-1.8 mm long; blade surfaces pubescent or glabrous.
16 Blades pilose; spikelets 1.1-1.6 mm long ............................................... D. strigosum var. strigosum
16 Blades glabrous, or sparsely pilose only near the adaxial base; spikelets 1.4-1.8 mm long ................
............................................................................................................. D. strigosum var. glabrescens
Key to the Dichanthelium acuminatum group
1 Internodes glabrous.
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......................................................................D. species 10 (=curtifolium)
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 Panicles 8-12 cm long, ¼-⅓ as wide, bearing 250 or more spikelets; spikelets 1.4-1.6 mm long; ligule (1.5-) 2-3
mm long; larger blades 7-11 cm long, often tinged with purple................................................................ D. spretum
3 Panicles 3-8 cm long, > ½ as wide, bearing < 200 spikelets; spikelets 1.1-1.6 mm long; ligule 2-5 mm long; larger
blades 4-10 cm long.
4 Longer hairs of ligule 2-3 mm long; spikelets 1.1-1.5 mm long; blades often tinged with purple, the larger 4-8
cm long................................................................................................................................... D. longiligulatum
4 Longer hairs of ligule 3-5 mm long; spikelets 1.4-1.6 mm long; blades often yellowish-green, the larger 5-10
cm long............................................................................................................D. acuminatum var. lindheimeri
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 blades 2-7 cm long, 2-7 mm wide.
6 Spikelets 0.8-1.1 mm long; blades 2-4.5 cm long, 2-5 mm wide; sheaths sparsely puberulent, lacking papillosebased
longer hairs.............................................................................................................................. D. wrightianum
6 Spikelets 1.1-1.7 mm long; mid-culm 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 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 .....................................................................................................D. leucothrix
7 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 ...........................................D. meridionale
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 4-12 cm long, 4-12 mm wide.
8 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; blades velvety-pubescent on abaxial surface.
9 Culms 15-60 cm tall and < 1.5 mm thick; panicle broadly ovoid, 5-8 cm long and > 1/2 as wide......................
...................................................................................................................... D. acuminatum var. acuminatum
9 Culms 40-70 (-80) cm tall, the larger usually > 60 cm long and > 2 mm thick; panicle contracted, 8-11 cm
long and < ½ as wide............................................................................................D. acuminatum var. thurowii
8 Sheaths and internodes of vernal culms glabrous, or papillose-pilose to hispid with ascending straight hairs 1-3
mm long; blades appressed-pilose to puberulent abaxially, but not velvety.
10 Peduncle, panicle axis, and often middle and upper internodes glabrous; sheaths, at least near mid-length,
lacking hairs or papillae; larger blades 4-8 mm wide, glabrous abaxially; spikelets 1.3-1.6 mm long................