GENERA OF GRASSES OF THE UNITED STATES. 229 
Annual er perennial grasses, of various habit. Species probably 
about 500, mostly confined to the warmer regions of both hemi- 
spheres, about 150 species being found in the United States. 
Type species: Panicum miliaceum L. 
Panicum L., Sp. Pl. 55, 1753; Gen. Pl., ed. 5, 29. 1754. Twenty species are 
described. The first ten and the fifteenth are now referred to other genera. Of 
the species considered typical by Linnezeus, as indicated by the description in 
his Genera Plantarum, Panicuwin miliacewm is the only one cultivated and is 
therefore chosen as the type.* 
Eatonia Raf., Journ. de Phys. 89: 104. 1819. <A single species, EH. purpura- 
scens, which is the same as Panicum virgatum, is included. 
Steinchisma Raf., Bull. Bot. Seringe 1: 220. 1830. ‘“ Panicum divaricatum, P. 
hians” are cited, both names applying to the same species, P. hians Hl. 
Phanopyrum (Raf.) Nash, in Small, Fl. Southeast. U. S. 104. 1903. Based 
on “ Panicum, subgenus Phanopyrum Raf.,” with a single species, P. gymnocar- 
pon (Ell.) Nash. 
Chasea Nieuwl., Amer. Midl. Nat. 2: 64. 1911. A new name proposed for 
“Panicum of the authors not of Linneus or only in part,’ the name Panicum 
being applied to Chaetochloa. 
Among the species of the United States two subgenera are recog- 
nized, besides Panicum proper. 
Subgenus Paurochaetium Hitche. and Chase. Perennials with 
tufted culms, erect narrow blades, narrow, more or less spikelike 
inflorescence, the ultimate branchlets produced beyond the uppermost 
spikelets as a bristle 1 to6 mm. long, the apiculate fruits transversely 
rugose. There are four species within our limits, one from Florida, 
three from Texas. This subgenus shows a transition to Chaetochloa. 
Subgenus Dichanthelium Hitche. and Chase. Perennials forming 
a usually well-marked rosette of winter leaves, having a vernal phase 
of simple culms and terminal panicles of small, perfect, but usually 
sterile spikelets, and an autumnal phase produced by the branching 
of the culms after the maturity of the primary panicles, the sec- 
ondary leaves and panicles usually much reduced, the spikelets cleis- 
togamous and fruitful, sometimes hidden in the sheaths. There are 
105 species within our limits, the species being especially abundant 
on the Atlantic Coastal Plain. A representative of this subgenus is 
Panicum dichotomum lL. (fig. 138). A common species in the East- 
ern States is P. clandestinum L. (Pl. XVII), one of the most robust 
representatives of the group. This has bristly sheaths and cordate 
clasping blades as much as an inch wide. It grows in moist soil and 
furnishes a moderate amount of forage. 
The remaining species belong for the most part to true Pani- 
eum, called by some the subgenus Eupanicum. The more important 
of these are the following: Panicum barbinode Trin., Para grass, a 
perennial with stout stolons as much as 15 feet long, culms 3 to 6 feet 
tall from a creeping base, bearded nodes, and panicles 4 to 6 inches 
long, consisting of several spikelike racemes of glabrous spikelets 
* For a full discussion of the type species of Panicum, see Hitchcock and Chage, Contr. 
U. 8S. Nat. Herb. 15: 18. 1910. 
