GRIFFITHS—-THE GRAMA GRASSES. 365 
without description in an earlier? paper, See also U. 8. Dept. Agr. Div. Bot. Bull. 
121: pl. 42. 1890. 
Chondrosium tenue Willd.; Beauv. Ess. Agrost. 158. 1812. Beauvois publishes 
‘* Actinochloa tenuis Willd. mss.’’ on page 41 and makes the above combination in his 
index on page 158. He, however, gives no description. In his private copy of the 
above-cited work he has written “= Bouteloua simplex Lag. and Actinochloa, Roe- 
mer.’’ See also H. B. K. Nov. Gen. & Sp. 1: 176. pl. 57. 1816. Plainly distin- 
guishable by the figure and description, 
Actinochloa procumbens Roem. & Schult. Syst. Veg. 2: 417. 1817. Based upon 
Chloris procumbens. 
Actinochloa tenuis Willd.; Roem. & Schult. Syst. Veg. 2: 418. 1817. Chondrosium 
tenue H. B. K. is cited as a synonym. 
Actinochloa prostrata Roem, & Schult. Syst. Veg. 2: 419.1817, Based upon Boute- 
loua prostrata, 
Eutriana tenuis Trin. Gram. Unifl. 240. 1824. Based upon Actinochloa tenuis Willd. 
Chloris filiformis Poir.; Kunth, Rév. Gram. 1: 93.1829. Mentioned as a synonym 
of Chondrosium lenue. 
Chloris tenuis Poir.; Kunth, Rév. Gram, 1: 93. 1829. A herbarium name cited as 
synonym of Chondrosium tenue. 
Chondrosium? prostratum Kunth, Rév. Gram. 1: 94. 1829. Based upon Bouteloua 
prostrata Lag. See also Sweet. Hort, Brit. 1: 455. 1826; Fourn, Mex. Pl. 2: 138. 1881. 
Bouteloua tenuis Griseb. Abh. Ges. Wiss. Géttingen 19: 211. 1874. (Plantae 
Lorentzianae.) Based upon Chondrosium tenue. 
Bouteloua pusilla Vasey, Bull. Torrey Club 11: 6. 1884. The type, in the National 
Herbarium, was collected by Vasey at Kingman, New Mexico, June, 1881. 
DESCRIPTION. 
A small, smooth, cespitose, prostrate or ascending, sparingly branched, annual, 
attaining its best development above an altitude of 1,600 meters; sheaths smooth, 
striate, with reduced, shortly pubescent ligules and few narrow blades only 2 to 3 cm, 
long; spikes solitary, 1.5 to 2 cm. long, revolute toward maturity, fertile to the end of 
the rachis; spikelets consisting of one lower fertile floret and an upper rudiment; glumes 
keeled, acuminate, pointed but awnless, the first smooth, about 3 mm, long, the second 
minutely hispid on the keel and 4 to 5 mm, long; lemma broadly oval, with 3 hispid, 
unequal awns, the central the longest and expanded with wing-like projections below; 
palet broadly obovate, smooth, broadly rounded above, about 3 mm, long, rudiment 
consisting of 3 equal, hispid awns, about 4 mm. long, together with 2 or 3 very small 
scales upon a naked stipe bearing a tuft of white hairs at its apex; caryopsis about 2 
mm. long, 0.75 mm. wide, obovate, the scutellum covering the entire ventral and 
curving back over a portion of the dorsal surface. (Figure 27.) 
When thinly distributed, especially upon loose fertile soils, this species forms large 
bunches which are more likely to be prostrate than when the plants are crowded and 
smaller. 
As a forage plant it is of very little value on account of its diminutive size and the 
ease with which it pulls up when grazed. Indeed, it has never been met with in 
sufficient abundance to be much of a factor in feed production. 
Specimens representing my conception of the species are Pringle 6450, 11218, 
Palmer 176, 332, 503, 712, Metcalfe 583. Pringle 1434, Chihuahua, and 6450, Federal 
District of Mexico, and Schaffner 156, San Luis Potosi, approach the heavy-spiked 
a Var. Cienc, 24: 141. 1805. 
