HITCHCOCK AND CHASE NORTH AMERICAN PANICUM. 247 



t^ 147. Paniciun columbianum Scribn. 



Panicum heterophyllum Bosc; Nees, Agrost. Bras. 227. 1829, not Spreng. 1822. 

 Based on "Panicum heterophyllum Bosc, Herb. Willd." The type specimen, in the 

 Willdenow Herbarium, labeled in Bosc's hand, is the vernal form. 



Panicum columbianum Scribn. U. S. Dept. Agr. Div. Agrost. Bull. 7 : 78./. 60. 1897. 

 "Dry sandy fields, meadows and open woodlands. New England and southward to the 

 Carolinas, and westward to Tennessee and Alabama, mostly near the coast; also in 

 California." The type, the specimen from which figure 60 is drawn, is in Hitchcock's 

 herbarium. It is labeled as follows in Scribner's wiiting: "Panicu7n columbianum 

 Scribn. (Type) Brookland, D. C, July 14, 1894. Coll. F. L.-S." The specimen con- 

 sists of three branching culms, 25 to 38 cm. high, the primary panicles destitute of 

 spikelets. A duplicate type is in the National Herbarium. 



Panicum psammophilum Nash, Bull. Torrey Club 26: 576. November, 1899, not 

 Welw. July, 1899. "New Jersey: * * * Toms River, July 25-31, 1898, PF. iV. 

 Clute, no. 175 (type)." This specimen, in the herbarium of the New York Botanical 

 Garden, consists of five branching culms, 15 to 40 cm. high, the primary panicles desti- 

 tute of spikelets. The lower internodes are appressed-pilose, but otherwise the speci- 

 men is very similar to Scribner's type. 



This species has been erroneously referred to Panicum unciphyllum Trin.a The 

 specimen sent as a portion of the type from the Trinius Herbarium is P. columbianum, 

 but a subsequent examination of Trinius's plants showed that there were two groups 

 of specimens lying loose upon a single sheet, one group being the type of P. unciphyllum 

 (P. tenue Muhl.), the other group being P. columbianum. A plant of the latter had 

 been sent with a copy of the label of the former. 



DESCRIPTION. 



Vernal plants light grayish green, often purplish; culms tufted, 15 to 50 cm., rarely 

 60 cm., high, stiffly ascending, densely crisp-puberulent with long, ascending, crimped 

 hairs commonly intermixed toward the base, but much less copiously than in P. 

 tsugetorum; sheaths shorter than the internodes, less pubescent than the culms, some- 

 times puberulent between the nerves only; ligules 

 less than 1 mm. long; blades firm, ascending or erect, 

 3 to 6 cm. long (seldom over 5 cm. long), 3 to 5 mm. 

 wide, broadest at the rounded base, the serrulate, 

 often white, cartilaginous margin usually involute 

 toward the acuminate apex, typically glabrous on 

 the upper surface but sometimes sparsely pilose toward 



the base, densely appressed-puberulent to glabrous 



, ^, ' • 1 r. r i ^ / 1 r \ 1 ^i^. 267.— P. columManum. From 



beneath; panicles 2.5 to 4 cm. (rarely 5 cm.) long, type specimen. 



about three-fourths as wide, the lower branches 



ascending, the axis and branches puberulent to nearly glabrous; spikelets 1.5 to 1.6 



mm. long, 1 mm. wide, obovate, obtuse, turgid, densely short-pubescent; first glume 



one-third to scarcely half as long as the spikelet, acute or subacute; second glume 



and sterile lemma subequal, scarcely covering the fruit at maturity; fruit 1.3 mm. 



long, 0.9 mm. wide, broadly elliptic, obtuse. 



Autumnal culms branching from the middle and upper nodes at the maturity of the 

 primary panicles, becoming widely spreading or decumbent at base, the early branches 

 sometimes nearly equaling the primary culm, the ultimate branchlets in short, 

 appressed fascicles, the crowded blades usually equaling or exceeding the reduced 

 panicles; winter blades thickish, lanceolate, often sparsely pilose or ciliate. 



Specimens of this species and the preceding often closely resemble each other, 

 since both vary much in pubescence and somewhat in habit. Panicum, columbianum 



a Hitchcock, Bot. Gaz. 41 : 66. 1906. 



