GRIFFITHS THE GRAMA GRASSES. 



415 



the Gray Herbarium and in the National Herbarium. Number 739 in the herbarium 

 of the Paris Museum, as stated above, has, on the same sheet, both wide a and narrow & 

 spikes, common in this species. 



Atheropogon americanus depauperata[us] Fourn. Mex. PI. 2: 139. 1881. Fournier 

 cites Bouteloua juncifolia Lag. and Eutriana lagascae Kunth as synonyms. He men- 

 tions two specimens, the first is one from Karwinski in the St. Petersburg Herbarium 

 with neither number nor locality; the other is Wright 739. ' It is evident from his 

 description and the citation of the last speci- 

 men that he had in mind Bouteloua porphy- 

 rantha Wright. He is evidently wrong in his 

 interpretation of Lagasca. 



Heterosteca rhadina Nash, Bull. Torrey Club 

 30 : 386. 1903. Heller's no. 6057, near Ponce, 

 Porto Rico, in the New York Botanical Gar- 

 den, is the type. Duplicates are widely dis- 

 tributed. Some of these duplicates show the 

 same facts exhibited by Wright 739 in the 

 herbarium of the Paris Museum. 



DESCRIPTION. 



Plants mostly low, spreading, sometimes 

 erect, but mostly reclined, and often nearly 

 prostrate and stoloniferous, perennial; culms 

 freely branching; spikes 4 to 10, variable, 

 1.5 to 3 cm. long, 2 to 6 mm. wide; spikelets 

 4 to 7, about 12 mm. long including awns, 

 2-flowered, the lower perfect or pistillate, 

 the upper stamina te; glumes nearly equal, 

 scabrous-keeled ; lemma of lower floret short- 

 awned, with lateral awns shorter than the 

 central, smooth, coriaceous, about 8 mm. 

 long; lemma of upper floret smooth, coria- 

 ceous 10 to 12 mm. long, with long awns, the 

 lateral slightly shorter than the central; 

 palet smooth, 8 mm. long, very short-awned 

 sulcate, on the back between the two nerves, 

 the edges involute; caryopsis about 3 mm. 

 long. 0.7 mm. wide, pointed below and contracted above (immature). (Figure 59.) 



The species, as it occurs in the West Indies, is very variable in every particular. 

 The spike and spikelet characters are especially subject to variation. The above 

 characterization is drawn from Brother Le6n's no. 861 in so far as spike and details 

 are concerned, amended from Curtiss (West Indian Plants) 546 and others, as to plant 

 characters. The Curtiss specimen in the National Herbarium shows two distinct 

 forms of spikes, one as here described and figured, and the other resembling B. ameri' 

 carta. Kunth figured c the wide-spiked form. The majority of the specimens show 

 a true perennial character, while B. americana is evidently an annual. In habit and 

 general aspect the species presents all sorts of variations from an erect plant, with 

 branching culms, to a low prostrate plant, with often long-geniculate to prostrate 



Fig. 59. — Bouteloua heterostega. a, Spikelet; b, 

 c, lemma and palet of first floret; d, e, lemma 

 and palet of second floret (rudiment attached 

 to palet). a, Scale 5; b-e, scale 7.5. From 

 Ledn 861. 



a Bouteloua humboldliana Griseb. 

 b Bouteloua porphyrantha Wright. 

 cH. B. K. Nov. Gen. & Sp. 1 : 173. pi. 54. 1816. 



9368°— 12- 



