

354 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



TBIAENA 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. pi. 9./. 4- 1812. Beauvois's figures, 

 although diagrammatic, appear to me well to characterize the plant. Desvaux a 

 distinguishes this from his T. americana which is Aristida americana L. 



Triaena racemosa H. B. K. Nov. Gen. & Sp. 1: 179. pi. 61. 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 Presl, 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. PI. 2 : 141. 1881. 



Eutriana? cristata Kunth, Enum. PI. 1: 281. 1833. Based upon Dineba cristata 

 Presl. 



Triathera gracilis Fourn. Mex. PI. 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 "Eutriana racemosa Trin. Msc. in Herb. Petrop." 

 as a synonym. 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 Museum at Paris, as well as in the herbarium 

 at Vienna, belongs here without doubt. The latter is labeled Eutriana racemosa 

 Trin. (See Eutriana racemosa Trin.) 



Bouteloua triaena Scribn. Proc. Acad. Phila. 1891: 307. /. 2fi 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 rudimenl, 



a Journ. de Bot. 1: 67. 1813. 



b In Beal's Grasses of North America (2 : 427. 1896) this figure is incorrectly trans- 

 ferred to B. texana. 



