396 CONTRIBUTIONS FROM THE NATIONAL, HERBARIUM. 



ment, this in the proximal spikelet very much reduced; first glume 5 mm., the second 

 6 mm. long, scabrous-keeled; lemma 6 to 7 mm. long, 3-awned, the central awn about 

 1 mm. longer than the lateral, smooth, the awns scabrous; palet 2-awned, smooth, the 

 awns scabrous; rudiment consisting of a staminate floret, the lemma bearing 3 long, 

 scabrous awns, about 11 mm. long, lateral awns about 2 mm. shorter; palet similar to 

 but smaller than that of the perfect floret; caryopsis cylindrical-ovate, 4 mm. long, 

 0.75 mm. wide, the large scutellum three-fourths the length of the entire caryopsis or 

 more. (Figure 48.) 



The type specimens furnish most of the knowledge which we have of this species, 

 which grows upon rocky ridges on the Pacific coast of the State of Sonora, Mexico. 

 It is very distinct from any of the other species. It resembles B. aristidoides in general 

 habit but is a coarser, more leafy plant, and the spikes are more like those of B. texana. 



Judging from the material in the National Herbarium this should be found com- 

 monly on the Pacific coast of Mexico, south from the State of Sonora. Besides the 

 type specimens there is one collected by Earl Flint in Granada, Nicaragua, in Febru- 

 ary, 1868, which is at least very close to this species. Confirmatory material from 

 Nicaragua is necessary. 



19. Bouteloua aristidoides (H. B. K.) Grieeb. 



Dinebra aristidoides H. B. K. Nov. Gen. & Sp. 1 : 171. 1816. The plate of this <* in 

 a later volume identifies the species without doubt. 



Atheropogon aristidoides Roem. & Schult. Syst. Veg. 2 : 415. 1817. Based upon 

 Dinebra aristidoides H. B. K. See also Spreng. Syst. Veg. 1 : 293. 1825; Fourn. Mex. 

 PL 2 : 139. 1881. 



Eutriana aristidoides Trin. Gram. Unifl. 242. 1824. Based upon Atheropogon aristi- 

 doides H. B. K. See also Steud. Syn. PL Glum. 1 : 216. 1854. 



Dineba hirsuta Presl, Rel. Haenk. 1 : 292. 1830. The type specimen is in the her- 

 barium of the National Museum at Prague. 



Eutriana f hirsuta Kunth, Enum. PL 1 : 280. 1833. Based upon Dineba hirsuta 

 Presl. 



Aristida unilateralis Willd.; Steud. Nom. Bot. ed. 2. 1 : 132. 1840. A herbarium 

 name of Willdenow published as a synonym of Eutriana aristidoides. 

 . Bouteloua aristidoides Griseb. Fl. Brit. W. Ind. 537. 1864. Based on Dinebra aristi- 

 doides H. B. K. See also U. S. Dept. Agr. Div. Bot. Bull. 12 » : pi. 35. 1890; U. S. 

 Dept. Agr. Div. Agrost. Bull. 7 : 214./. 196. 1897. 



Bouteloua gracilis Hook.?; Vasey in Wheeler, Rep. U. S. Surv. 100th Merid. 6 : 287. 

 1878, not Lag. 1840. The type is Rothrock's no. 701. 



Bouteloua ciliata Griseb. Abh. Ges. Wiss. Gottingen 19 : 302. 1879 (Symb. Fl. 

 Argent.). The type specimen, Lorenz & Hieronymus 352, from Juramento, Argentina, 

 is in the Grisebach Herbarium. 



Triathera aristidoides Nash in Small, FL Southeast. U. S. 137. 1903. 



DESCRIPTION. 



A tufted, erect or decumbent, smooth annual, with upright or geniculate culms, 

 altogether too variable in size to permit of the preparation of lineal descriptions of any 

 value; sheaths loose, especially on branching culms, striate, the lower one-third to 

 one-half the length of the internode, the upper sometimes nearly as long, this depend- 

 ing upon the character of the season; ligule reduced to a membranaceous line or 

 slightly fimbriate, with a few scattered hairs; blades small, few, 2 to 7 cm. long, with 

 a few scattered hairs on the upper surface; panicle variable, 2 to 7 or 8 cm. long, but 

 often in vigorous plants 15 cm. long, bearing normally 10 to 14 spikes, but under 



a Op. cit. 7 : pi. 695. 1825. 



