354 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
TRIAENA H. B. K. 
Triaena H. B. K. Nov. Gen. & Sp. 1: 178. 1816. A monotypic genus based upon 
T. racemosa. 
Inflorescence linear, racemose, the spikes arranged in two rows on opposite sides 
of a flattened axis but so twisted upon their short delicate peduncles as to appear 
unilateral; spikes consisting of a single 2-flowered spikelet and a prolonged rachis, 
the lower floret perfect, the upper reduced to a 3-awned rudiment. 
1. Triaena juncea (Desv.). 
Triathera juncea Desv.; Beauv. Ess. Agrost. 40. pl. 9. f. 4. 1812. Beauvois’s figures, 
although diagrammatic, appear to me well to characterize the plant. Desvaux¢ 
distinguishes this from his T. americana which is Aristida americana L. 
Triaena racemosa H. B. K. Nov. Gen. & Sp. 1: 179. pl. 62. 1816. Easily identified 
from the figures and description, See also Roem. & Schult. Syst. Veg. 2: 421. 
1817. 
Eutriana triaena Trin. Gram. Unifl. 239. 1824. Based upon Triaena racemosa H. 
B. K. 
Atheropogon triaena Spreng. Syst. Veg. 1: 293.1825. Based upon Triaena 
racemosa H. B. K. 
Atheropogon domingensis Spreng. Syst. Veg. 1: 293.1825. Based upon Tri- 
athera juncea Desv. 
Dineba cristata Pres], Rel. Haenk. 1: 293.1830. The type, in the Bohemian 
National Museum at Prague, has been examined. 
Triathera racemosa Desv. Opusc. 72. 1831. Based on Triaena racemosa H. B. K. 
See also Roem. & Schult. Syst. Veg. 2: 421. 1817; Fourn. Mex. Pl. 2: 141. 1881. 
Eutriana? cristata Kunth, Enum. Pl. 1: 281. 1833. Based upon Dineba cristata 
Presl. 
Triathera gracilis Fourn. Mex. Pl. 2: 141. 1881. I have no hesitancy in referring 
this to Triaena juncea, although Fournier says distinctly that his plant is not Triaena 
racemosa H. B. K. Fournier cites ‘‘ utriana racemosa Trin. Msc. in Herb. Petrop.”’ 
asasynonym, All specimens so named by Trinius belong to Bouteloua curtipendula. 
The first specimen cited by Fournier is Berlandier’s no. 1016 from Cuernavaca, Mexico, 
This number in the herbarium of the Muséum at Paris, as well as in the herbarium 
at Vienna, belongs here without doubt. The latter is labeled Hutriana racemosa 
Trin. (See Lutriana racemosa Trin.) 
Bouteloua triaena Scribn. Proc. Acad, Phila, 1891: 307. /. 2.0 1891. Based upon 
Triaena racemosa H. B. K. See also Bull. Torrey Club 18: 314. 1891. 
DESCRIPTION. 
A cespitose, erect, sparingly hairy perennial, forming strong, conspicuous bunches 
among other grasses or more rarely continuous pure growths approaching a rough, 
bunchy turf; culms sparingly branched, erect or when luxuriant geniculate, 40 to 
50 cm. high; sheaths rather close, striate, covered with long, scattered, papillose hairs, 
these more numerous in plants of exposed places; blades narrow, comparatively 
short, the lower about 7 cm., the upper 5 cm. long, erect, acuminate, rigid, involute, 
smooth save for the regularly arranged, marginal, papillose hairs; panicle slender, 
racemose, 7 to 10 cm. long, the spikes bilateral but usually so curved on their peduncles 
as to appear unilateral; spikes variable in number, 20 to 70, about 7 mm, long at anthesis 
but becoming 10 to 12 mm. long by the development of the awns of the rudiment, 
@ Journ. de Bot. 1: 67. 1813. 
6 In Beal’s Grasses of North America (2: 427. 1896) this figure is incorrectly trans- 
ferred to B, texana. 
