POLYGONACEOUS GENERA. 41 
in pools along the Platte, near Denver, August, 1881, L. F. 
Ward, and at New Windsor, Weld Co., 31 July, 1894, Geo. E. 
Osterhout. 
P. oropHYLLA. Evidently 2 or 3 feet high, suberect, slightly 
flexuous ; very short-peduncled but ample leaves elliptic-lanceo- 
late, abruptly acuminate, the narrow base subauriculately 
rounded at the insertion of the petiole, the largest 5 or 6 inches 
long, 2 in width, deep green above and scarcely roughened by 
the faint though not very sparse minute strigose hairiness, be- 
neath paler, inconspicuously strigose with longer softer hairs, 
the midvein conspicuously clothed with very long comparatively 
soft hairs that are rather ascending than appressed ; both the 
short thin ocre and the striate internodes pubescent with very 
straight and closely appressed hairs; short peduncle similarly 
appressed-pubescent and not glandular: bracts of the short 
spike long-hairy both on the back and along the margin ; flowers 
small for the plant. 
In swamps at Dallas, Texas, 11 Oct, 1900, J. Reverchon, 
distributed by B. F. Bush, to U. S. Herb., under n. 2146. Spe- 
cies particularly well marked by the long-soft hairiness of the 
midvein of the leaf beneath. 
P. ABORIGINUM. Of the size of the last, rather more slender, 
the geniculate stems more or less decumbent; leaves narrower, 
exactly lanceolate, though with subcordate or subauriculate 
base, rather obviously soft-strigose above, more densely and 
silkily so beneath, where the midvein is clothed with very straight 
and closely appressed long fine hairs: peduncles rather densely 
appressed-villous without glands; spike short, not surpassing 
the leaves; bracts villous-strigose: flowers small; small chest- 
nut-brown achenes orbicular and little compressed, almost 
apheroidal. 
Species of Oklahoma and the Indian Territory, collected by 
Mr. Blankinship, 28 Aug., 1895. 
P. Lanetorsir. Evidently upright, several feet high. the 
comparatively slender stems with notably short and thick nodes, 
the striate internodes 14 to 2 inches long; leaf blades elliptic- 
