20 Rhodora [FEBRUARY 
Wyoming; no. 359 O. B. Metcalfe from New Mexico; nos. 26,248, 
26,247 and 26,246 J. Macoun from Ontario. 
5a. MUHLENBERGIA FOLIOSA ambigua Scribn. n. comb. Muhlen- 
bergia ambigua Torr. in Nicollet's Rept. 164(237). 1843. M. 
sylvatica Auct. in part. Lemmas awned; awns 4-10 mm. long, 
Otherwise as in the species. 
A specimen of the type collection of Muhlenbergia ambigua is in 
the National Herbarium. Other specimens referred here are no. 
26,244 J. Macoun; no. 80 Wm. Harriot; no. 525 M. L. Fernald, 
1893; no. 527 M. L. Fernald, 1894. A specimen from Delaware, 
collected by A. Commons in 1897, has panicles rather more closely 
flowered and more rigid than usual. An awnless counterpart of 
this form was collected by C. R. Ball in Ohio in 1892. "The pres- 
ence of a more or less developed second floret noted in the original 
diagnosis of M. ambigua, occurs in other species of this group. 
5b. MUHLENBERGIA FOLIOSA setiglumis Scribn. n. comb. M. 
sylvatica setiglumis S. Wats. U. S. Geol. Expl. Exped. 40th Par. 
5:378. 1871. ‘‘Glumes attenuate into a scabrous bristle 24-3 
lin. long; the palet with its awn about twice longer” (S. Wats. 
l. e). The habit of this subspecies is entirely that of Muhlen- 
bergia foliosa and the plant differs from M. foliosa ambigua only 
in the awn-like prolongation of the glumes beyond the floret as in 
M. racemosa. A specimen from the type collection is in the Na- 
tional Herbarium, no. 1,288 S. Watson, from near Warm Springs, 
Humboldt Pass, Nevada. ‘To this subspecies are referred no. 
2,838 T. A. Williams from Wyoming; no. 3 Williams from 
South Dakota; no. 927 Griffiths & Morris from Oregon and 
no. 2 F. P. Briggs from Bradley, Maine, In Briggs’ specimen 
the glumes equal or much exceed the florets in different spikelets 
in the same panicle. 
6. Muhlenbergia umbrosa Scribn. n. nom. Agrostis sylvatica 'Torr. 
Fl. U. S. 1: 87. 1824, not Linn. 1762. Agrostis diffusa Muhl. 
Gram. 64. 1817, not Host 1809. Muhlenbergia sylvatica gracilis 
Seribn. Trans. Kans. Acad. Sci. 9:116. 1885, not M. gracilis 
Kunth 1829. 
Muhlenbergia sylvatica Torr. & Gray was based upon Agrostis 
sylvatica Torrey, who changed the name from Agrostis diffusa Muhl. 
because of an earlier Agrostis diffusa by Host, apparently overlooking 
the much earlier Agrostis sylvatica of Linnaeus. There being no 
