HITCHCOCK AND CHASE—NORTH AMERICAN PANICUM. 289 
174. Panicum leibergii (Vasey) Scribn. 
Panicum scoparium liebergii Vasey, U. 8S. Dept. Agr. Div. Bot. Bull. 8: 32. 1889. 
‘“*P. liebergii Scribn.)” is given as synonym, and ‘‘Plymouth County, Iowa (John 
Lieberg) ” [error for Leiberg] is cited. The type, consisting of two vernal culms, is in 
Hitchcock’s herbarium. The accompanying label reads: ‘‘Panicum Leibergii, 
Scribn. 1884. Plymouth Co., Iowa. 1878. Legit John Leiberg,’’ the specific 
name, author, and date being in Scribner’s writing. On the sheet is written in Vasey’s 
hand,.‘‘P. scoparium var. Leibergii V.’’ 
Panicum scribnerianum leibergii Scribn. U. 8. Dept. Agr. Div. Agrost. Bull. 6: 
32. 1897. No synonym is cited and ‘‘South Dakota: Brookings (Wilcox 16)” is the 
only specimen mentioned. This name must however be considered a new combina. 
tion based on P. scoparium leibergii Vasey. The Wilcox specimen agrees With that 
of Leiberg. 
Panicum liebergvi Scribn. in Britt. & Brown, Ilust. Fl. 3: 497. 1898. Based on 
““Panicum scoparium Lam. var. Liebergii Vasey.’? This name was first mentioned 
as a synonym under P. scoparium liebergii Vasey. 
DESCRIPTION. 
Vernal form dull green, in clumps of few to several slender culms, 25 to 75 cm. 
high, erect from a more or less geniculate base, pilose to merely scabrous; sheaths 
shorter than the internodes, papillose-hispid with spreading hairs; ligules almost 
obsolete; blades ascending or erect, rather thin, 6 to 15 cm. long, 7 to 15 mm. wide, 
narrowed toward the rounded base, acuminate, papillose-hispid on both surfaces, 
often sparsely so above, papillose-ciliate from one-third to half their length; 
panicles finally long-exserted, 8 to 15 cm. long, less than half as wide, the flexuous 
branches narrowly ascending or somewhat spreading at anthesis; spikelets 3.7 to 4 
Fig. 325.—P. leibergii. From type speeimen. 
mm. long, 1.8 to 2 mm. wide, oblong-obovate, turgid, strongly papillose-hispid with 
spreading hairs; first glume more than half the length of the spikelet, pointed, second 
glume and sterile lemma subequal, covering the fruit at maturity or the lemma slightly 
exceeding it; fruit 3 mm. long, 1.7 to 1.8 mm. wide, obovate-oval. 
Autumnal form more or less leaning, sparingly branching from the middleand lower 
nodes late in summer, the branches mostly simple, erect, the blades scarcely reduced, 
usually exceeding the short-exserted panicles. 
aU.8. Dept. Agr. Div. Bot. Bull. 8: 32. 1889. 
41616°—voxt 15—10——19 
