1902] Merrill, — Notes on North American Grasses 143 



juncea Linn., and S. juncea, Lam., and accordingly Dr. Britton erred 

 in taking the name Oryzopsis juncea. Stipa canadensis Poir. was 

 based on Michaux's S. juncea. Panicum firmum Knnth, was based 

 on Milium pungens Torr., which is certainly Oryzopsis canadensis. 

 The descriptions of Oryzopsis parvifora Nutt. and Urachne brer ica it- 

 data Trin. certainly apply to Oryzopsis juncea. Muhlenberg's descrip- 

 tion of his Milium No. 3, without name {Milium muhlenbergianum 

 Schultes) scarcely applies to Oryzopsis juncea but is so referred for 

 the present. 



Muhlenbergia expansa (Poir.) Trin. Uniflor. 193. 1824. 



Stipa expansa Poir. in Lam. Encycl. Suppl. 7 : 453. 1806. 



Trichochloa expansa DC. Hort. Monsp. 151. 1813. 



Agrostis rubicunda Bosc. 1. c, as syn. 



Agrostis trichopodes Ell. Sk. Bot. S. C. and Ga. 1 : 135. pl.8,f. /., 



1817. 



Muhlenbergia trichopodes Chapm. Fl. So. U. S. 553. i860. 



There has been some uncertainty as to the identity of Stipa expansa 

 Poir., as it has previously been confused with Agrostis arachnoidea 

 Poir., which is a synonym of Muhlenbergia capillaris (Lam.) Trin. 

 Poiret's full descriptions leave no doubt as to the identity of both 

 these species and his Stipa expansa is certainly the species described 

 by Elliott as Agrostis trichopodes. DeCandolle and Trinius also have 

 full descriptions of the species in question. As Poiret's name is the 

 oldest available one, it should be taken up for the species now known 

 as Muhlenbergia trichopodes (Ell.) Chapm. 



Deschampsia arctica (Spreng.). 



Deschampsia brevifolia R. Br. Suppl. App. Parry's Voy. 291. 182 1, 



non Aira brevifolia Bieb. Fl. Taur. Cauc. 3: 63. 18 19; Aira 



arctica Spreng. Cur. Post. 32. 1827; Trin. Mem. Acad. St. 



Petersb. VI. Sci. Math. Phys. et Nat. 1 : 56. 183 1. 



Recently Mr. Nash x correctly considering Deschampsia brevifolia 

 R. Br. an untenable name, changed to Deschampsia brachyphylla, 

 and extended the range of the species south in the mountains to 

 Montana and Wyoming, overlooking the fact that there was already 

 an available published name for the species, Aira arctica Spreng., 

 which was based on Deschampsia brevifolia R. Br., and which must 

 be retained for the species. 



A careful study of Robert Brown's original description of this 

 species, its geographical distribution and an examination of all avail- 

 able material is convincing of the fact that Mr. Nash erred in his 

 interpretation of this species, and that his Deschampsia brachyphylla 

 {Deschampsia curt/folia Scribn.) is not at all the plant described by 

 Robert Brown. 



There is in the TJ. S. National Herbarium a specimen from Grin- 



1 Nash in Ryd. Mem. N. Y. Bot. Gard. i : 37. 1900. 



