4 8 Rhodora [March 



range is on sandy shores, light, moist or rather dry soils, etc., from 

 Nebraska and South Dakota to California and Washington. 



Sporobolus simplex thermale var. nov. A rather robust 

 annual 2.5 to 3 dm. high, with numerous, short plane leaves about 

 2 mm. wide, and purplish, exserted, rather densely flowered, almost 

 spikelike panicles 2.5 to 4 cm. long, 3 to 4 mm. in diameter. Spike- 

 lets 2 mm. long, the flowering glume scabrous, acute, mostly awnless. 



Type specimen collected on the margin of a stream of hot water, 

 Lolo Hot Springs, Montana, 302a David Griffiths, Sept. 17, 1898. 

 No. 302 Griffiths, same locality and date, is also referred here. 



This variety could with equal propriety be referred to Sporobolus 

 filiformis (Thurb.) Rydb., but is distinguished from both Sporobolus 

 filiformis and S. simplex by its more robust habit, and densely flowered 

 panicles. In its awnless flowering glumes it approaches nearer the 

 former although in general aspect it resembles Sporobolus simplex, 

 but lacks the awned flowering glumes of that species. 

 Sporobolus aristatus Rydb. Bull. Torr. Bot. Club. 28: 266. 1901. 



In his description of this species Dr. Rydberg cites three specimens, 

 2196 and 27 Tweedy from Wyoming, and 1281 S. Watson from Utah. 

 We have had access to the two latter numbers and after a most minute 

 examination of those specimens we have been unable to distinguish 

 this species from Sporobolus simplex Scribn. and must consider it only 

 a depauperate form of that species. The presence of an awn to the 

 flowering glume is an exceedingly variable character, and even in the 

 type of Vilfa depauperata filiformis Thurb. {Sporobolus filiformis Rydb.) 

 awned and unawned spikelets are found on the same plant. 



Sporobolus gracilis (Trin.) n. comb. 



Vilfa gracilis Trin. Agrost. I : 52. 1840 ; not Trin. 1. c, 82. 



Vilfa subsctacea Trin. 1. c, Arabic ill. 



Agrost is juncea Michx. Fl. Bor. Am. 1 : 52. 1803, not Lam. Encycl. 

 1 : 60. 1783. 



Heleochloa juncea Beauv. Agrost. 24. 18 12. 



Colpodium junccum Trin. in Spreng. Neue. Entd. 2: 37. 182 1. 



Sporobolus junceus Kunth, Rev. Gram. 1 : 68. 1835. 



Sporobolus ejuncidus Nash in Britt. Manual 106. 1901. 



There are in the U. S. National Herbarium spikelets from Trinius's 

 type of Vilfa gracilis ivom the St. Petersburg Academy, the type locality 

 of which is " Carolina." It is very evident from examination of these 



