GRIFFITHS—THE GRAMA GRASSES. 417 
symmetrical; glumes scabrous-keeled, the first reduced nearly to an awn, 5 mm, 
long, the second wider, 7 to 8 mm. long; lemma 5 to 6 mm, long, smooth, with 3 short 
awns, the lateral awns slightly longer than the central; upper floret simply a 3-awned 
rudiment with a few scales at base or a well-developed perfect floret, but always, 
except in the lower spikes, bearing a long central awn, the lemma, including awn, 
10 to 14 mm. long, the lateral awns often not more than 6 or7 mm. long. (FicureE 60.) 
The first specimen of this species which I have recognized is Schott 741, in the 
herbarium of the Field Museum of Natural History. The floral characters of B, 
disticha are exceedingly variable, as is true of 
many of the species of this group. The descrip- 
tion is drawn from the upper spikelets. The 
lower ones are small and often staminate only, 
the rudiment being reduced to three imperfectly 
developed, short awns. 
The species is exceedingly rare in collections. 
The chief diagnostic character is the inflorescence 
and the apparent bilateral arrangement of the 
spikelets, which is admirably brought out in 
Kunth’s figures. 
Besides the Schott specimen the following are 
typical: Curtiss 537, from Cuba; Pittier 10374, 
from Costa Rica; and Leén 299, from Cuba. Pittier 
2537, Canal Zone, is a geniculate form with branch- 
ing culms. 
34. Bouteloua pilosa (Hook.) Benth. 
Eutriana pilosa Hook. f. Trans. Linn. Soc. Bot. 
20: 173, 1851; Steud. Syn. Pl. Glum. 1: 216. 
1854. The Macrae specimen from Albemarle 
Island, cited by Hooker, has not been examined. 
My knowledge is based upon Andersson 46, from 
Galapagos, and Fendler 2521, from Venezuela, in 
the Grisebach Herbarium. More recently many 
fine specimens have been examined in the Gray 
Herbarium from the Hopkins Galapagos Expedi- 
tion (Snodgrass & Heller 655). F ee pe Bouieloa me * Spiele 
Eutriana gracilis Hook. f. Trans. Linn. Soc, Bot. d, OT dimentary second floret: ¢, midi 
20: 175. 1851, not Bouteloua gracilis Hook.“ nor mentary floret of lowermost spikelet; 
Lagasca.o The type of this species has been  /, two views and cross section of cary- 
examined through the courtesy of the director ors @, Seale 5; BJ, scale 10. From 
of the Royal Botanic Gardens of Kew, England. nodgrass & Heller 655 in Gray Herb. 
Bouteloua pilosa Benth.; Wats. Proc. Amer. Acad. 18: 179. 1883. Based upon 
Eutriana pilosa Hook. f. 
DESCRIPTION. 
An erect, cespitose, smooth annual(?) 20 to 40 cm. high; culms slender, often 
branching; sheaths close; blades flat, thin, often 10 cm. long, the ligule an incon- 
spicuous ring of short hairs; inflorescence racemose, 10 to 20 cm. long; spikes vari- 
able, from 15 to 35, bilateral, on a zigzag rachis, but usually appearing unilateral; 
@ Vasey in Wheeler, Rep. U.S. Surv. 100th Merid, 6: 287. 1878. 
bSteud. Nom, Bot. ed. 2. 1: 219. 1840. 
