HITCHCOCK AND CHASE—NORTH AMERICAN PANICUM. 139 
80. Panicum rudgei Roem. & Schult.¢ 
Panicum scoparium Rudge, Pl. Guian, 1:21. pl. 29. 1805, not Lam. 1798. No par- 
ticular locality in Guiana is mentioned by Rudge. In the Berlin Herbarium is a 
specimen from Rudge which is authentic though it probably is not the type. The 
original description and the plate leave no doubt as to the identity of the species. 
Panicum rudget Roem. & Schult. Syst. Veg. 2: 444. 1817. Based on ‘Pan. 
scoparium Rudge.” 
Panicum rudgei brasiliense Raddi, Agrost. Bras. 48. 1823. ‘Species rarissima 
observata tantum in viciniis fluminis Jnhu- 
mirim.”’ We have not seen the type of this, 
but the description applies to the type of P. 
rudget. 
Panicum dasytrichum Spreng. Syst. Veg. 
1: 317. 1825. ‘‘Brasil.” The type, in the 
Sprengel Herbarium, was collected by Hoff- 
mansegg. 
Panicum hirsutum Willd.; Spreng. Syst. 
Veg. 1: 317. 1825, not Swartz, 1797. This 
is given as a synonym under P. dasytrichum 
and is credited to “‘W. herb.” The type, 
in the Willdenow Herbarium, was collected 
by Hoft . i Fia. 133.—P. rudgei. From Salzmann’s 
»y Holimansege 1 Brazil. specimen of P. rigens. 
Panicum rhigiophyllum Steud. Syn. PI. 
Glum. 1:76.1854. ‘“P.rigens. Salzm. Hrbr. Bahia.” This specimen was not found 
in the Steudel Herbarium, but a Salzmann specimen bearing this name was examined 
at Halle. 
a The following species, though not North American, may here be described on 
account of its relationship to Panicum rudget: 
Panicum rotundum sp. nov. 
Plants perennial, in small tufts; culms 30 to 50 em. high, rather stout, stiff, erect or 
somewhat geniculate at base, densely ascending-hirsute, the nodes densely bearded ; 
sheaths, except the upper, mostly shorter than the internodes, hirsute like the culms; 
ligules membranaceous, ciliate, the hairs mingling with those of the blade; blades thick, 
erect or appressed, linear, 5 to 20 cm. long, 2 to 5 mm. wide, more or less involute, at 
least toward the long-acuminate apex, only as wide as the sheath at, base, the juncture 
obscure, densely hirsute on the upper surface, 
harshly velvety beneath; panicles terminal and in 
the axils of the upper | to3 leaves, forming an oblong 
inflorescence as in P. rudgei, about one-third the 
height of the plant, the main axis pilose, the slender, 
angled, scabrous, stiff but flexuous branchlets as- 
cending or spreading, pilose in the axils, the long 
pedicels divergent; spikelets 2.3 to 2.5 mm. long, 1 
to 1.2 mm. wide, very turgid, abruptly pointed, 
strongly nerved, a few stiff, appressed hairs here 
and there between the nerves; first glume over half 
the length of the spikelet, abruptly pointed; sec- 
ond glume and sterile lemma subequal, exceeding the fruit, the lemma subtending 
a palea and staminate flower; fruit 1.8 mm. long, 1 mm. wide, ellipsoid, smooth and 
shining, a broad scar at the base. 
Fia. 134.—P. rotundum. From 
type specimen. 
