(GRASS FAMILY.) 643 



23. MUHLENBERGIA, Schreber. DROP-SEED G. (PL 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 with the enclosed 

 grain, often equal, the glume 3-nerved, mucronate or awned at the apex. 

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

 American botanist of the early part of this century.) 



1. MUHLENBERGIA 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 ; the simple contracted panicle very slender or filiform ; lower glumes barely 

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

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

 Mich., Minn., and southward. Aug. Spikelets less than 1" long. 



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

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

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

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

 very acute flowering 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. Ill 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 with more slender panicles. 



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

 -*- Lower glumes long and bristle-pointed. 



4. M. sylvtica, 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 

 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 ascending, clustered and branching, 1 

 high ; panicles contracted, densely many-flowered ; spikelet ^-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 the 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. 



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



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

 sparingly branched ; contracted panicle slender , loosely flowered ; lower glumes 



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