11 



in size may result from the specimens being of more vigorous growth than those 

 seen by Trinins, and will not warrant the separation of the 8i)ef'ies without a 

 comparison with the type. 

 Mulilenbergia flaviseta Scribu. sp. nov. (Plate VII). A slender, erect, glabrous per- 

 ennial, witli simple, scape-like culms 2 to 3 dm. high, short, creeping rootstocks, 

 flat leaves which are crowded at the base, and terminal, rather densely-flowered 

 panicles 2 to 6 cm. long. Leaves of the culm 2 fco 3, hardly exceeding tliose of 

 the innovations. Sheaths striate, glabrous, longer than the interuodes; ligule 

 very short, ciliate, decurrent; leaf Idades 5 to 10 cm. long, the upjiermost 1 to 2 

 cm. long, 2 to 4 mm. wide, gradually ta^iering from the base to the long attenuate- 

 pointed, scabrous tips, scabrous on the margins and strongly scabrous on the 

 upper surface. Panicle branches solitary, compound, naked below, more or less 

 spreading in anthesis, scabrous, as are the very short pedicels. Spikelets 3 to 4 

 mm. long exclusive of the awns ; outer glumes thin and somewhat scarious, very 

 i:nequal, the first one-fourth to nearly one-half the length of the second, which 

 • is 2 to 3 mm. long, oblong-lanceolate and subacute, the a^iex being minutely 

 ciliate with a few short hairs; flowering glume narrowly lanceolate, 3-nerved, 

 minutely scabrous on the midnerve above, very shortlj^ and minutely barbate at 

 the base; palea a little shorter than the glume, scabrous near the acute tip. 

 Awn yellow, 15 to 18 mm. long, arcuate or flexuose, minutely scabrous. No. 

 834, E. Palmer, Mexico, 1896. 



This rather showy siJocies is related to Muhlenberyia gracilis, from which, how- 

 ever, it is readily distinguished by its much more slender and scape-like culms, 

 shorter panicle, and yellow, flexuose awns. 



•'This grass was found at Dos Cajetes, 30 miles nearly west from Durango, on 

 the road to Otiuapa, altitude 8,500 feet, among pines and oaks, October 23, 1896. 

 Many plants grew together along the 8lo]ies of ravines. The color of the tops 

 gives a verj' showy a^ipearance, distinguishing the grass from everything around 

 it. But the animals did not appear to like it, because it was noticed that none 

 of the tops had been eaten off. It is a very abundant grass."' (E. Palmer.) 



