120 CONTRIBUTIONS FROM THE NATIONAL HERBABIUM. 
© 68. Panicum cupreum nom. nov. 
Panicum hians purpurascens Scribn. Proc. Acad. Phila. 1891: 296. 1891, netP. 
purpurascens BK 4815. ‘‘(3449) [Pringle] * * * Wet hollows in prairies of 
Flor de Maria, State of Mexico. September 4.” The type is in Hitchcock’s herba- 
rium. It was collected in 1890. 
DESCRIPTION. 
Plants perennial, in small tufts; culms simple, erect, 40 to 60 cm. high, slender, 
wiry, glabrous; leaves somewhat clustered at the base, the sheaths keeled, glabrous, 
the lower overlapping, the upper shorter than the inter- 
nodes; ligules fimbriate, scarcely 0.5 mm. long; blades 5 to 15 
cm. long, 2 to 4 mm. wide, at the base scarcely as wide es the 
sheaths, erect or ascending, folded and more or less twisted, 
glabrous or with a few long hairs on the upper surface at the 
base; panicles very long-exserted, 3 to 11 cm. long, dark pur- 
ple, composed of a few distant, slender, appressed or ascending 
branches, naked about half their length, bearing short, 
crowded branchlets with densely clustered spikelets along the 
upper half or toward the ends; spikelets 3 mm. long, about 
1.2 mm. wide, and at maturity nearly twice as thick, rather 
Fic. 113.—P. cupreum. strongly nerved; first glume one-third the length of the spike- 
Brom type specimen of 16¢ or less, obtuse, concave along the midnerve; second glume 
P. hians purpurascens ; 2 
Soripa and sterile lemma equal, exceeded by the enlarged sterile 
palea, the lemma strongly concave along the midnerve below; 
fruit 2.4 mm. long, 0.8 mm. wide, the margins of the lemma more inrolled than in 
P. hians, the apex tipped with a minute bit of hyaline membrane. 
This species is allied to P. hians, from which it is chiefly distinguished by the 
larger, more congested spikelets, with shorter, concave first glume and concave sterile 
lemma. 
The type collection, Pringle’s no. 3449, two specimens of which we have seen, is 
the only one known of this species. 
Stolonifera.—Plants perennial, decumbent at base or widely creeping and rooting 
at the nodes; culms branching, pubescent in lines or glabrate; sheaths (except 
in P. biglandulare) with a dense line of pubescence at the summit; ligules mem- : 
branaceous, nearly obsolete; blades lanceolate or ovate-lanceolate, acuminate 
and with a pubescent, petiole-like base; panicles composed of few to several 
short, densely-flowered racemes along a main axis, a tuft of pubescence at the bases 
of the rachises; spikelets short-pediceled, mostly in 2’s, secund along the lower 
side of the rachis, strongly nerved, the second glume and sterile lemma scabrous 
on the midnerves toward the summit, exceeding the smooth and shining fruit. 
Spikelets hispid and with 2 crateriform glands on the sterile 
lemma; second glume and sterile lemma not boat-shaped. 
Spikelets not over 2mm. long; blades not over 4 cm. long. 66. P. pulchellum. 
Spikelets 3.6 mm. long; blades 4 to 10 cm. long.-.....--- 67. P. biglandulare. 
Spikelets glabrous, glandless; second glume and sterile lemma 
boat-shaped. 
Blades not over 5 cm., usually 2 or 3 cm. long; second 
glume rather blunt and shorter than the sterile 
Ikes onli gs Vse eeu eR ae eels mip uaty sea NS C  S eat 64. P. stoloniferum. 
Blades 5 to 11 cm. long; second glume acute, nearly equal- 
tor) 
imeythemsteriellemimaee- = seeee eeee ee 65. P. frondescens. 
