98 POACEAE 
(BLACK OAT- a )—Rocky or sandy nes thiekets and old fields, various 
provinces, Fla. to Tex., Mich. and Mas 
50. MUHLENBERGIA Schreb. Low or moderately tall perennials, the 
stems simple to much branched, the inflorescence a narrow or open panicle. 
Spikelets 1- des glumes usually shorter than.the lemma, obtuse to acuminate 
r awned, the first sometimes small, rarely obsolete; lemma membranaceous, 
3- to idle) with a very short usually minutely mE ig the acute Spe 
sometimes extending into a straight or flexuous mueronate only. 
Eighty species, mostly in Mexico and the SW Dui States —HAIR-GRASSES. 
Plant A creeping scaly rootstocks: glumes at least half as long as the 
flor I. TENUIFLORAE. 
Plant without creeping scaly rootstocks, but base sometimes de- 
mbent and rooting. 
Panicle more 2 dnd contracted, not diffuse: stems branched: 
Jeaf-blades II. SCHREBERIANAE. 
Panicle diffuse. the branches capillary: stems simple: leaf- 
blades involute. III. EXPANSAE. 
I. TENUIFLORAE 
Stem erect, ultimately somewhat branched above: leaf-blades divaricate: glumes 
e oad ao thin, shorter than the "body of the lemma: panicles slender, loosely 
Spikelets 1.5-2 mm. m lemmas awnless or short-awned. 1. M. sobolifera. 
Spikelets 3-4 mm. long: lemmas long-awned. 2. M. tenuiflora. 
Stem much-branched, Boon ' spreading: leaf-blades ascending or 
erect: glumes narrow, acuminate, about as long as the body 
Stem glabrous below the nodes 3. M. mexicana. 
Stem minutely DB below the nodes. 
emma long-awned. M. umbrosa. 
.. M. foliosa. 
ou 
Lemma inuccondte or short- awned. 
CHREBERIAN 
S 
pne with weak stem and brnthes: leaf-blades d mostly 2-3 
wide. 6. M. Schreberi. 
l III. EXPANSA 
EE shorter than the ae sometimes aaa glumes half 
to % as long as the T. M. expansa. 
Awn longer than the lemma ; ' glumes, excluding awns, less than 
half as long as the lem 8. M. capillaris. 
1. M. uie ie Trin. Pies d slender, 30—80 em. tall: leaf- 
blades as mueh as em. long, 3— wide: paniele 5-15 em. long: glumes 
a half > $55 as the acumina e o 
provinces, Tenn. to Tex., Wis. N. H., and 
Va. 
2. M. tenuiflora (Willd. B. S. P. Ste 
60—100 cm. tall: vied eae 6-18 em. ine, 
wide 
mostly 8 mm. wl more: panicle 10-25 
em. long: glumes Bn. adnate, half to 
4% as long as the floret: awn oi lem 5- 
4 oret: ma 
10 mm. long. [M. Willdenovii Trin.]— —Rocky 
woods a dry hillsides, various provinces, 
Tenn. to Ark., Wis., and Vt. 
3. M. mexicana (L.) Trin. Stem 50-100 
em. long, sprawling: panicle 5-15 cm. long, 
the branches appressed (nc Dg i a an- 
thesis ) ; spike- ike: spikelets s 2.5 " long.—Moist places, rich woods, and 
prairies, various provinces, N. C. o Tex, N. D., and N. B. 
