112 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
obsolete; fruit 2.1 mm. long, 0.8 mm. wide, acute, thin in texture, scabrous toward 
the summit. 
This species seems to be more nearly related to P. polygonatum than to any other, 
for which reason it is placed, though somewhat doubtfully, in this group. 
DISTRIBUTION. 
Swamps, Mexico. 
Mexico: Jalapa, Pringle 8195, Schiede & Deppe 674 (Halle Herb.). 
58. Panicum polygonatum Schrad. 
Panicum polygonatum Schrad. in Schult. Mant. 2: 256. 1824. “Jn Brasilia, ad 
ripas fluvit Ilhéos. Princeps Sereniss. Maxim. Neowidens.’’ The type, in the herba- 
rium of the Botanical Garden in St. Petersburg, has a large pan- 
icle, pubescent. nodes, and a few bristles on the rachis. 
Panicum potamium Trin. Gram. Pan. 239. 1826. ‘Brasil. 
(LaNasporrr).’’ The type, in the Trinius Herbarium, is from 
near Mandioca, Brazil, collected by Langsdorff ‘in udis aquosis 
puris.”’ This name is spelled ‘‘P. potamicum”’ by Steudel.¢ 
Fig. 107.—P. polygo- = Panicum hydrophilum Trin.; Nees, Agrost. Bras. 208. 1829, 
veehnete tyPe This is given asasynonym under P. dubium Lam., the specimen 
referred to as “* (Langsdorff.— V. in Herb, Trin.),’’ doubtless being 
the basis of this name. We have not seen this specimen, but Trinius ? refers to this 
name in a note under P. potamium as ‘‘olim P. hydrophilum mihi dictam.”’ 
Setaria polygonata Kunth, Rév. Gram. 1: 47. 1829. Based on Panicum polygo- 
natum Schrad. 
Panicum trichogonum Willd.; Steud. Nom. Bot. ed. 2. 2: 261. 1841. This is given 
as a synonym under P. polygonatum Schrad. with the following citation: ‘‘ Willd. 
hrb. (Sec. Trin. mpt.).’’ The type, in the Willdenow Herbarium, is labeled 
‘“‘Amer. merid. Humboldt.”’ 
Panicum pilosum polygonatum Doell in Mart. FI. Bras. 27: 211. 1877. Based on 
P. polygonatum Schrad. 
Panicum bourgaei Fourn. Mex, Pl, 2: 25. 1886, This name was earlier listed by 
Hemsley ¢ without description. Fournier cites a single specimen, ‘In valle Cordo- 
vensi, januario (BourG[EAu] n. 1662 part.).’? The specimen of this number seen at 
Halle is P. polygonatum, while the one in the Gray Herbarium is P. larum. The 
original description calls for a plant with pubescent nodes, which would indicate 
P. polygonatum. 
DESCRIPTION. 
Plants rather freely branching from the lower nodes, widely spreading from a decum- 
bent or creeping base, rooting at the nodes; culms 20 to 100 cm. long, the nodes densely 
pubescent; sheaths shorter than the internodes or sometimes nearly equal, densely 
ciliate, otherwise glabrous or hirsute toward the summit; ligules less than 0.5 mm. long; 
blades ascending or spreading, oblong-lanceolate, 3 to 13 cm. long, 8 to 15 mm. wide, 
usually ciliate at the cordate base, otherwise glabrous or occasionally sparsely hirsute; 
panicles 7 to 20 cm. long, about half as wide, the lower branches solitary, distant, 
spreading, the upper sometimes in pairs, the numerous raceme-like branchlets secund 
from the lower side of the branches, the somewhat clustered, short-pedicled spikelets 
also secund on the branchlets, the rachises sparsely pilose with long, weak hairs, or 
a Syn. PL. Glum. 1:71. 1854, 
b Mém. Acad. St. Pétersh. VI. Sci. Nat. 1: 266. 1834. 
¢ Biol. Centr. Amer. Bot. 3: 486. 1885. 
