Part 7 - UNC Herbarium

POACEAE 864
4 Second glume and sterile lemma acute to short-acuminate, conspicuously longer than the fertile lemma; spikelets
glabrous (occasionally sparsely pubescent in D. scabriusculum).
5 Panicle rachis pellucid-punctate; ligule a stramineous to light brown membrane, with or without terminal
ciliations; peduncle and often internodes scabrous; first glume 0.3-0.6 (-0.8) mm long, reniform to suborbicular ....
........................................................................................................................................................D. scabriusculum
5 Panicle rachis not pellucid-punctate; ligule entirely of white hairs; peduncle and internodes smooth; first glume
0.7-1.2 mm long, ovate to lanceolate ................................................................................................... D. yadkinense
4 Second glume and sterile lemma blunt to subacute, shorter than, equaling, or barely exceeding the fertile lemma;
spikelets pubescent (sometimes sparsely so in D. clandestinum).
6 Sheaths, at least the lower, papillose-hispid with spreading hairs; blades 10-28 cm long.................D. clandestinum
6 Sheaths glabrous, puberulent, finely pubescent, or sparsely pilose; blades 5-18 cm long.
7 Ligule 0-0.3 mm long; spikelets 2.2-3.2 mm long, 1.1-1.3 mm wide; first glume 0.7-1.4 (-1.8) mm long .........
.................................................................................................................... D. commutatum var. commutatum
7 Ligule 0.4-0.7 mm long; spikelets 2.9-3.9 mm long, 1.6-2.0 mm wide; first glume 1.5-2.2 mm long................
....................................................................................................................................................... D. latifolium
Key D - Spikelets 2.1-3.2 mm long, larger culm blades < 13 mm wide,
at least the lower culm nodes bearded with a usually spreading-ascending collar
of dense and/or longish hairs
1 Ligule with a dense ring of short hairs 0.5-1 mm long in front of a usually less dense ring of longer hairs (pseudoligule) 1-5
mm long.
2 Nodes retrorsely bearded; internode and sheath hairs spreading to restrorse; blade surfaces velvety-pubescent or longpilose.
3 Spikelets 2.5-3.2 mm long; longer hairs of pseudoligule 1-3 mm long; blade surfaces velvety-pubescent; panicle
rachis densely pubescent; [of cedar glades and dry limestone soils]...........................................[D. malacophyllum]
3 Spikelets 1.8-2.5 mm long; longer hairs of pseudoligule 3-5 mm long; blade surfaces long-pilose; panicle rachis
sparsely pilose; [of dry sandy soil of pine and oak woodlands] ......................... D. villosissimum var. villosissimum
2 Node beard hairs spreading to ascending; internode and sheath hairs ascending to appressed; blade surfaces glabrate to
appressed-pubescent.
4 Spikelets 2.5-3.1 mm long; lower culm blades usually glabrous adaxially except for long hairs at or near the
margin (appearing ciliate), appressed-pubescent abaxially ........................................................... D. ovale var. ovale
4 Spikelets 2.1-2.6 mm long; lower culm blades usually sparsely appressed-pubescent on both surfaces, eciliate or
ciliate at the base only.............................................................................................................D. ovale var. addisonii
1 Ligule a single structure, without a pseudoligule.
5 Ligule 2-5 mm long, ciliate.............................................................................................................D. acuminatum group
5 Ligule < 2 mm long, ciliate or membranous.
6 Ligule a stramineous to light brown membrane, with or without terminal ciliations; peduncle scabrous but not
hairy.
7 Panicle rachis smooth, pellucid-punctate; first glume 0.3-0.6 (-0.8) mm; larger leaves 10-25 cm long, 8-15
mm wide; ligule 0.5-1.3 mm long; lowest elongate culm internode > 2 mm in diameter; lowest nodes usually
glabrous or pubescent..............................................................................................................D. scabriusculum
7 Panicle rachis scabrous, not pellucid-punctate; first glume 0.7-1.1 mm long; larger leaves 7-12 cm long, 6-9
mm wide; ligule 0.3-0.6 mm long; lowest elongate culm internode < 1.7 mm in diameter; lowest nodes
usually retrorsely bearded .................................................................................... D. species 9 (= cryptanthum)
6 Ligule entirely of white hairs; peduncle variously hairy or glabrous, but not scabrous.
8 Culms to 1.5 m tall, with a broad, glabrous, viscid band below the nodes; blades of the lower leaves typically
villous or velvety-pubescent.......................................................................................................... D. scoparium
8 Culms rarely exceeding 1 m, without a viscid band below the nodes; blades various.
9 Sheaths retrorsely pilose with hairs 2-3 mm long; basal leaves usually numerous, ascending, similar in
size and shape to the culm leaves; culms branching only at the base .................................... D. laxiflorum
9 Sheaths glabrous or pilose (if pilose, then hairs not both retrorse and 2-3 mm long); basal leaves rosetteforming,
usually much smaller than the culm leaves; culms branching at the nodes in age.
10 Culm internodes glabrous to sparsely pilose; culm nodes bearded with long retrorse hairs; blade
surfaces glabrous to velvety-pubescent ........................................................... D. dichotomum group
10 Culm internodes, at least the lower, strigose, pilose, or villous; culm nodes bearded with ascending
or spreading hairs; blade surfaces glabrous or variously hairy.
11 Lower nodes bearded with erect-ascending, soft, and long hairs; mid-culm blades usually 20×
or more as long as wide.
12 Spikelets 2.9-4.0 mm long, fusiform to elliptic, acute, basally constricted; first glume 1.4-
2.6 mm long.....................................................................................................D. fusiforme
12 Spikelets 1.5-3.1 mm long, obovate to elliptic-obovate, obtuse to sub-acute, not basally
constricted; first glume 0.6-1.5 mm long.