Part 7 - UNC Herbarium

POACEAE 866
11 Spikelets 2.1-2.9 mm long, elliptic or obovate, rounded or pointed at the summit, the nerves often
raised, but not broad and thick.
12 Culm internodes and sheaths glabrous or sparsely pilose.
13 Spikelets obpyriform when viewed dorsally, strongly plano-convex when viewed
laterally; first glume and base of second glume usually strongly reddish-purple ................
.............................................................................................. D. species 2 (=webberianum)
13 Spikelets variously shaped but not obpyriform when viewed dorsally, biconvex to elliptic
when viewed laterally; first and second glumes various.
14 Culms tending to be stiffly erect; blades erect or erect-spreading, broad, usually but
not always tapering from just below the middle to both ends, often yellowish green;
plants not or only sparingly branched in age, not developing leafy fascicles of
reduced leaves and inflorescences .............................................................. D. boreale
14 Culms not stiffly erect; leaves usually spreading, broad or narrow, dark to bright
green; plants often freely branched in age, becoming top-heavy with a mass of
fascicled, reduced leaves and inflorescences ............................D. dichotomum group
12 Culm internodes crisp-puberulent (sparsely so in D. species 2 (=webberianum); sheaths
puberulent or glabrous.
15 Spikelets elliptic, sub-acute to pointed, greenish or faintly purple-tinged basally ...............
.................................................................................................. D. commutatum var. ashei
15 Spikelets strongly plano-convex when viewed laterally, obpyriform when viewed
dorsally, broadly rounded, usually markedly reddish-purple basally.
16 Fertile lemma and palea papillose; spikelets 2.2-2.6 mm long; lower culm blades 6-
12 mm wide, glabrous................................................... D. species 2 (=webberianum)
16 Fertile lemma and palea smooth (minutely reticulate but not papillose); spikelets
(1.8) 1.9-2.2 (-2.3) mm long; lower culm blades 4-8 mm wide, glabrous, glabrate, or
puberulent (especially abaxially) ......................................D. species 3 (=lancearium)
Key F - Spikelets 0.8-2.0 mm long, lower culm internodes variously hairy
1 Longer hairs of ligule 2-5 mm long.
2 Ligule without a distinct ring of short hairs in front of the long hairs.............................................D. acuminatum group
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 ...................................................................................................................D. meridionale
3 Peduncle panicle axis hairs > 0.1 mm long; sheaths and internodes densely clothed with straight retrorse
(occasionally spreading to spreading-ascending) hairs often > 4 mm long.................................................................
........................................................................................................................... D. villosissimum var. villosissimum
1 Longer hairs of ligule < 2 mm long.
4 Culm leaves basally crowded, ascending, usually matted or cushion-forming, larger than the mid and upper culm
blades.
5 Sheaths conspicuously retrorsely long-pilose; longer blades 6-18 cm long and 7-12 mm wide; spikelets 1.9-2.3
mm long ................................................................................................................................................ D. laxiflorum
5 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.
6 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.
7 Blades 1.5-4 (-5) cm long; spikelets 0.9-1.2 mm long.....................................................D. chamaelonche
7 Blades 4-12 (-20) cm long, some at least 7 cm long; spikelets 1.2-1.5 mm long ........................................
............................................................................................................[D. dichotomum var. glabrifolium]
6 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.
8 Spikelets pubescent, 1.5-2.1 mm long; blade surfaces glabrous............. D. strigosum var. leucoblepharis
8 Spikelets glabrous, 1.1-1.8 mm long; blade surfaces pubescent or glabrous.
9 Blades pilose; spikelets 1.1-1.6 mm long ............................................... D. strigosum var. strigosum
9 Blades glabrous, or sparsely pilose only near the adaxial base; spikelets 1.4-1.8 mm long ................
............................................................................................................. D. strigosum var. glabrescens
4 Culm leaves not basally crowded, the lowest leaves spreading and rosette-forming, usually smaller than the culm
leaves.
10 Blades of mid-culm leaves typically long and stiff, acuminate, linear or narrowly lanceolate, often involute, only
2-5 mm wide when < 8 cm long.............................................................................................................. D. aciculare
10 Blades of mid-culm leaves lanceolate, thin or firm but not stiff, usually > 5 mm when > 8 cm long.
11 Internodes crisp-puberulent.