graminetE. (grass family.) 643 



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



Spikelets 1 -flowered, in contracted or rarely in open panicles. Empty glumes 

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

 smaller or minute. Flower very short-stalked or sessile, the glume and palet 

 usually minutely bearded at base, herbaceous, deciduous \vith the enclosed 

 grain, often equal, the glume 3-uerved, mucronate or awued at the apex 

 Stamens 3. (Dedicated to the Rev. Dr. Henri/ Muhlenberg, a distinguislied 

 American botanist of the early part of this century.) 



§1. MUHLEXBERGIA proper. Panicles contracted or glomerate, on branch- 

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



* Flowering glume barely mucronate or sharp-pointed. 



1. M. SObolifera, Trin. Culms ascending (1-2° high), rarely branch- 

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

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

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

 Mich., Minn., and southward. Aug. — Spikelets less than \" long. 



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

 or simple; panicle (2-3' long) oblong-linear, contracted into an interruj)fed 

 glomerate s/j^l-e, long-peduncled, the branches sessile; glumes awned, nearly 

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

 very acute flow^eriug glume and palet. — Bogs and 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 S. 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, linear (green and purplish) ; lower glumes awnless, 

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

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



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



H- Lower glumes long and bristle-pointed. 



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

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

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

 floivering 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 ascending, 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 base of the lower flower ; lower glumes nearly equal, long-pointed ; 

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

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

 A remarkable species, approaching Brachyelytrum in the structure of the 

 spikelet, but with wholly the habit of Muhlenbergia. 



1- -t- Lower glumes short or minute, not or scarcely pointed. 



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

 sparingly branched ; contracted /)anic/e slender, loosely flowered ; lower glumes 



