140 PKOCEEDINGS OF THE AMERICAN ACADEMY 



villous and the lower axils more or less bearded, tlie tuft reduced 

 sometimes to only one or two hairs, as described by Trinius, the 

 upper axils usually glabrous. The Poa nitida of Elliott appears to be 

 a distinct species, having the branches of the panicle ascending, with 

 the few spikelets terminal on long pedicels, and the glumes very 

 acute, but less pointed than in E. campestris. It is wholly smooth 

 and glabrous excepting the beard at the throat of the sheaths and 

 a moderate roughness on the panicle and sometimes on the leaves. 

 As the name Erarjrostis nitida has been applied by Link to a differ- 

 ent grass, this may be called E. Elliottii. 



Glyceria guandis, Watson, 1. c. 667. This grass has ordinarily 

 been referred to G. aquatica, Smith {Poa aqualica, Linn.), of which 

 it was made a variety by Torrey in his early publications. Recently 

 it has been named G. arundinacea, Kunth, which is the same as 

 G. 7-emota, Fries. Our species differs from the last in its much 

 stouter habit, larger, more erect and more branched panicle, the 

 empty glumes broader, and the flowering glumes shorter, broader 

 in proportion, and more obtuse. From G. aquatica it differs in its 

 much narrower and smaller spikelets (2 or 3 lines long and 3-6- 

 flowered), the more acute lower glumes, and the flowering ones more 

 abruptly obtuse or truncate. 



PUCCINELLIA, Pari. (Atropis, Griseb.) Following Hackel, 

 Thurber, and others, this genus is kept distinct from Glyceria in the 

 revised Manual, especially as it is needed for a number of western spe- 

 cies which are not satisfactorily referable to either Glyceria or Poa. Its 

 separation leaves both these genera much more clearly defined. The 

 name Atropis, which originated with Trinius, is credited by Grisebach 

 for the genus to Ruprecht, Fl. Samoied. (1845). But reference to 

 the place cited shows that while Ruprecht was strongly disposed to 

 consider Dupontia, Arctophila, Atropis, Catabrosa and Phippsia as 

 equally good genera, and even used Dnpontia and Arctophila as 

 generic names upon the plates of some new species, yet throughout 

 his text and descriptions they are all alike treated as subdivisions of 

 the genus Poa. The perplexity under which he labored is shown by 

 the expression with which he closes his discussion of the possible 

 genera, — "Nubes et inania captant, qui generibus solum student, nee 

 speciebus simul cunctis." The genus was first definitely published by 

 Parlatore in 1848 under the name of Puccinellia, and then by Grise- 

 bach in 1853 as Atropis. 



