994 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
This species differs from /’. pedicellatum in its stiffer, short-jointed culms, shorter, 
puberulent, prominently ciliate blades, 
and pyriform spikelets with a shorter ee 
first glume. 
DISTRIBUTION, 
Oak woods in sand dunes, southern 
Texas and northern Mexico; appar- 
ently rare. 
Texas: Sarita, [Hitchcock 3865. 
Mexico: Matamoros, Berlandier 
988, 2418 (last two in Gray 
Herb.). 
Fia. 332.—Distribution of P. nodatum. 
Scoparia.— Vernal culms tall; blades flat, elongated, not over 1.5 cm. wide; ligules 
short; spikelets pointed, 7 to 9-nerved. 
Pubescence soft-villous or velvety; spikelets abruptly pointed. 
Vernal culms erect or ascending; plants velvety through- 
out; spikelets about 2.5 mm. long...............-- 178. P. scoparium. 
Vernal culms decumbent at base; the upper sheaths more 
or less glabrate; spikelets less than 2 mm. long..... 179. P. viseidellum. 
Pubescence when present not velvety. 
Spikelets elliptic; fruit 2 mm. long...............--.-.- 180. P. aculeatum., 
Spikelets ovate; that is, broadest below the middle; fruit 
2 mm. long or less. 
Sheaths or some of them hispid, rarely glabrous; au- 
tumnal form with crowded branchlets. ......-- 181. P. scabriusculum. 
Sheaths glabrous; autumnal form sparingly branching.182. P. eryptanthum. 
178. Panicum scoparium Lam. 
Panicum scoparium Lam. Encycl. 4: 744.1798. ‘‘Cette plante a été recueillie dans 
la basse Caroline par le citoyen Michaux.’’ The type specimen, in the Lamarck 
Herbarium, is a part of a vernal culm with a single leaf and over-mature panicle. The 
accompanying label reads, ‘‘ Panicum scoparium Lam. dict. donné par le C. Michaux.”’ 
Panicum pubescens Lam. Encycl. 4: 748.1798. The author refers to two specimens 
as follows: ‘‘J’ai vu de cette espéce un individu nain dans Vherbier de Vaillant; il 
V’avoit regue de Sherard en 1721. Le citoyen Michaux I’a trouvée dans la Basse- 
Caroline.’’ The first mentioned specimen is in the Paris Herbarium. It is some 
species of Brachiaria allied to Panicum villosum Lam. as described by Hooker. The 
other specimen referred to is in the Michaux Herbarium and consists of two freely 
branching autumnal culms of P. scoparium. The accompanying label reads ‘‘ Pani- 
cum pubescens Lam. Hab. in pratis sylvestribus Carolinae.’’ Since Lamarck’s 
description applies to the Michaux ® rather than to the Sherard specimen we may 
consider the Michaux plant the type. 
Panicum viscidum Ell. Bot. 8. C. & Ga, 1: 123. pl. 7. f. 3.¢ 1816. No specimen nor 
definite locality is cited. The type in the Elliott Herbarium is labeled: ‘‘ Panicum 
viscidum mihi. Hab: in humidis.’’ It consists of a single culm lacking the base, 
bearing several short branches and an over-mature primary panicle. 
Panicum pauciflorum Bosc; Spreng. Syst. Veg. 1: 313. 1825. This, together with 
P. scoparium Michx., is placed asa synonym under ?. pubescens Lam. We have seen 
no authentic specimen. 
«Fl. Brit. Ind. 7: 34. 1896. 
b See Hitchcock, Contr. Nat. Herb. 12: 147. 1908. 
¢ Plates 7 to 10 were issued with vol. 2. 1824. 
