Click the number at the start of a key lead to highlight both that lead and its corresponding lead. Click again to show only the two highlighted leads. Click a third time to return to the full key with the selected leads still highlighted.

Key to Dichanthelium, Key to the Dichanthelium acuminatum group

Copy permalink to share | Check for keys that lead to this key

1 Internodes glabrous (sometimes lowest internodes sparsely to moderately pubescent).

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  Dichanthelium curtifolium

Show caption*© Janet Wright, some rights reserved (CC BY-NC), uploaded by Janet Wright   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 Leaf blade basal cilia usually conspicuous; larger vernal blades 6-10 cm by 6-10 mm; internodes, especially lower, sometimes pilose; spikelets obovoid; plant often yellowish-green (orange-brown in age)  Dichanthelium acuminatum var. lindheimeri

3 Leaf blade basal cilia usually inconspicuous or absent; larger vernal blades 2.5-10 cm long, 2-9 mm wide; all internodes glabrous (rarely the lowest sparsely pilose); spikelets ellipsoid; plant often green to purplish.

4 Spikelets (0.9-) 1.1-1.5 mm long, moderately densely to densely puberulent, most hairs < 0.1 mm long; panicles 3-8 cm long, usually more than ½ as wide as long; larger blades 2.5-8 cm long  Dichanthelium longiligulatum

4 Spikelets (1.3-) 1.4-1.9 mm long, (glabrous-) sparsely to moderately pubescent, most hairs > 0.1 mm long; panicles 4-12 cm long, usually less than ½ as wide as long; larger blades 7-10 cm long  Dichanthelium spretum

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 leaf blades 2-7 cm long, 2-7 mm wide.

6 Spikelets 0.8-1.1 mm long; mid-culm leaf blades 2-4.5 cm long, 2-5 mm wide; sheaths sparsely puberulent to glabrous, lacking papillose-based longer hairs  Dichanthelium wrightianum

6 Spikelets 1.1-1.7 mm long; mid-culm leaf 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 leaf 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  Dichanthelium leucothrix

7 Larger mid-culm leaf 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  Dichanthelium 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 4-20 cm long, 4-12 mm wide.

8 Culms > 100 cm long; node pubescence densely retrorse; larger blades 12-20 cm long, 15-20 × as long as wide; spikelets 1.9-2.3 mm long, 2× or more as long as wide, acute  Dichanthelium species 16

8 Culms < 100 cm long (-rarely longer); node pubescence various; larger blades 4-12 cm long, < 15 × as long as wide; spikelets (1.0-) 1.1-2.0 mm long, less than 2× as long as wide, rounded to blunt.

9 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; leaf blades velvety-pubescent on abaxial surface, the margins ciliate (or appearing ciliate) for half or more their length.

10 Plants drying light green to yellow-green; culms usually < 60 cm long; lower internodes rarely more than 1.3 mm in diameter; panicles usually < 8 cm long; primary branching at most nodes before maturation of vernal panicle, longer branches often exceeding the culm  Dichanthelium acuminatum var. acuminatum

10 Plants drying olive-green, sometimes purplish; culms usually > 60 cm long; lower internodes usually > 2 mm in diameter; panicles usually 9-11 cm long; primary branching sparingly from middle nodes after maturation of vernal panicle, longer branches not exceeding culm  Dichanthelium thurowii

9 Sheaths and internodes of vernal culms puberulent, pubescent or papillose-pilose to hispid with ascending straight hairs, but never grayish-villous; leaf blades glabrous to variously pilose abaxially, but not velvety-pubescent, the margins eciliate or ciliate only below the middle.

11 Spikelets 0.8-1.1 mm long; blades 2-4.5 cm long, 2-5 mm wide  Dichanthelium wrightianum

11 Spikelets 1.1-2.0 mm long; blades 3-12 cm long, 3-12 mm wide.

12 Peduncle, panicle axis, and often middle and upper internodes glabrous; sheaths lacking hairs or papillae, at least near mid-length  Dichanthelium acuminatum var. lindheimeri

12 Peduncle, panicle axis, and internodes puberulent, pubescent, or pilose; sheaths papillose-pilose to hispid.

13 Leaf blades 5-12 cm long, 6-12 mm wide; spikelets 1.5-2.0 mm long; peduncle, panicle axis, and sheaths variously pilose, but lacking puberulent hairs 0.1 mm long  Dichanthelium acuminatum var. fasciculatum

13 Leaf blades 3-7 cm long, 3-7 mm wide; spikelets 1.1-1.7 mm long; puberulent hairs 0.1 mm long often present on peduncle, panicle axis, or sheaths.

14 Larger mid-culm leaf blades 4-7 cm long, 4-7 mm wide, glabrous to sparsely pubescent adaxially; ligule 1-5 mm long, the hairs of one series; spikelets 1.1-1.5 mm long  Dichanthelium leucothrix

14 Larger mid-culm leaf blades 3-6 cm long, 3-5 mm wide, long-pilose adaxially; ligule often with a short series of hairs <1 mm long in front of a series with hairs to 4 mm long; spikelets 1.3-1.7 mm long  Dichanthelium meridionale