I 



GRAMIXE.E. (<;KA.SS FAMILY.) C43 



23. MUHLENBERGIA, Schreher. Drop-seed G. (PI. 8. ) 



Spikolets l-flowered, in contraeted or rarely in open panicles. Empty glinne.s 

 mostly acute or bristle-jioiuted, persistent, usually thin; the lower rather 

 smaller or minute. Flower very short stalked or sessile, tl»e glume and palet 

 usually minutely bearded at base, herbaceous, deciduous with the enclosed 

 grain, often etpial, the glume 3-uerved, mucrouate or awned at the apex. 

 Stamens .3. (Dedicated to the Rev. Dr. Henrij Muhlenberg, a distinguished 

 American botanist of the early part of this century.) 



§1. MUHLENBERGIA proper. Panicles contracted or glomerate, on byanrh- 



ing rigid culms from scaltf creeping rootstocks ; leaves short and narrow. 



* Fluiririug glume barely mucronate or sharp-pointed. 



1. M. SObolifera, Triu, Culms ascending (I -2*^ high), rarely branch- 

 ing ; the simple contracted panicle very slender or filiform ; lower glumes barely 

 pointed, almost equal, one third shorter than the Jlower ; flowering glume ab- 

 ruptly short-mucronate, efjualliug the palet. — Open rocky woods, Mass. to 

 Midi., ^liuu., and southward. Aug. — S])ikelets less than \" loug. 



2. M. glomerata, Trin. Culms upright ( 1 -3° high), sparingly branched 

 or simple; ]>anicle (2-3' long) oblong-linear, contracted into an interrupted 

 glomerate spike, long-peduucled, the branches sessile ; glumes awned, nearly 

 equal, aud (with the bristle-like awn) about twice the length of the unequal 

 very acute flowering glume and palet. — Bogs aud wet rocks, common, espe- 

 cially northward. Aug. — Var. ram6sa, Vasey. A stout strict much-branched 

 leafy form, the lower glumes but little longer than the flower. 111. to Dak. 



3. M. Mexicana, Trin. Culms ascending, much branched (2-3° high) ; 

 panicles lateral and terminal, often included at the base, contracted, the branches 

 densely spiked-clustered, liueav (green and purplisli); lower glumes awnless, 

 sharp-pointed, unequal, the upper about the length of the very acute flowering 

 one. — Low grounds ; common. Aug. Varies with more slender panicles. 



* * Flowering glume hristle-awned from the tip ; flowers short-pedicelled. 



•*- Lower glumes long and bristle-pointed. 



4. M. sylv^tica, Torr. & Gray. (PI. 8, fig. 1, 2.) Culms ascending, much 

 branched aud diffusely spreading (2-4° long); contracted panicles densely 

 many-floivered ; lower glumes almost equal, bristle-pointed, nearly as long as the 



flowering one, which bears an awn twice or thrice the length of the spikelet. 

 — Low or rocky woods; common. Aug., Sept. 



5. M. ambigua, Torr. Culms a.scending, clustered and branching, 1° 

 high ; panicles contracted, densely many-flowered ; spikelet 2-flowered, the up- 

 per flower like the lower and perfect, or more frequently reduced to a mere 

 awn at the luise of the lower flower ; lower glumes nearly equal, long-pointed ; 

 flowering glume villous, as long as tlie lower and ecjualling the palet, its awn 

 nearly twice longer. — Minn, (shore of Elysian Lake, Waseca Co.. Geyer). — 

 A remarkable s])ecies, a])proaching Brachyelytrum in the structure of the 

 spikelet, but with wholly the habit of Muhlenbergia. 



M- H- Lower glumes short or minute, not or scarcely pointed. 



6. M. Willden6vii, Trin. Culms upright (3° high), slender, simple or 

 sparingly branched ; contracted /;a«i'c/t slender, loosely flowered ; loicer glumes 



