248 



CONTRIBUTIONS FEOM THE NATIONAL HEEBAEIUM. 



is typically smaller, more slender and stiff er than P. tsugetorum, and the culms are 

 densely crisp-puberulent Avith little of the pilose character of the latter. Occasional 

 specimens, like Bissell 5596, Chase 38^2, and Graves 10, are larger, laxer plants with 

 appressed-pilose culms and are referred to P. columbianum because the spikelets are 

 not over 1.6 mm. long. 



DISTRIBUTION. 



Sandy woods or open ground, Maine to Virginia. « s^ 



Maine: North Berwick, Purlin 1196; York Harbor, Bichnell in 1896. JJ 



New Hampshire: Laconia, Carter iw 1902 (Hitchcock Herb.). 

 Massachusetts: Wellesley, Smith 738; Framingham, Smith 742, 744 

 Connecticut: GrisWold, Graves 10; 



Waterford, Graves , 83, 84; 



Southington, Andrews in 1902, 



Bissell 5596. 

 New York: Van Cortlandt Park, 



Bichnell in 1891; Rockville 



Center, Bichnell in 1903 and 



1906; Cedarhurst, Bichnell in 



1903; Hempstead, Bichnell in 



1903; Jamaica, Bichnell in 



1905. 

 New Jersey: Tuckerton, Chase 



3606,3613; Atsion, Chase 3533, 



3539; Wildwood, Chase 3519; Toms River, Clute 175; Mount Arlington, 



Machenzie lS9d ; Lakehurst, Machenzie 2068; Chadwick, Mackenzie 2404; South 



Amboy, Machenzie 2247 ; Sussex County, Machenzie 2105. 

 Pennsylvania: Stroudsburg, Porter in 1898. 

 Maryland: Patuxent River, Hitchcock 1632; Chesapeake Junction, Hitchcock 



2407, 2413; Beltsville, Chase 3794, 3832; West Chevy Chase, Chase 5427. 

 District of Columbia: Chase 5429, 5430, Hitchcoch 2418, Saibner in 1894, 



Williams in 1896. 

 Virginia: Norfolk, Fosey in 1884 (Gray Herb.)..,; 



Fig. 268. — Distribution of P. columbianum. 



C^ 



147a. Panicum columbianiiin thioium Hitchc. & Chase. 



Panicum unciphyllum thinium Hitchc. & Chase, Rhodora 8 : 209. 1906. "Type 

 Chase 3577 in National Herbarium. In mats, sandy, open ground, Tom's River, N. J., 

 July 28, 1906; collected by Agnes Chase ". The type consists of a tuft of many autum- 

 nal culms 12 to 20 cm. high, the spikelets 1.3 mm. long. 



Panicum columbianum thinium Hitchc. & Chase in 

 Robinson, Rhodora 10:64.1908. Based on P. und- 

 2:)hyllum thinium Hitchc. & Chase. 



DESCRIPTION. 



Vernal culms shorter and more slender than in P. colum- 

 bianum, not over 30 cm. high, Usually about 20 cm. high, 

 densely tufted, the appressed jjubescence longer, stiffer, 

 and arising from minute papillae; sheaths sparsely ascending pilose; blades rarely over 

 3 cm. long, sparsely pilose with long hairs on the upper surface at least near the margin 



a The extended range given with the original description was based on misidentifi- 

 cation of various small specimens of P. lindheimeri, as shown by such specimens 

 labeled by Scribner "Panicum columbianum" in the National Herbarium and in 

 Hitchcock's herbarium. 



Fig. 269. — P. columbianum thini- 

 um. From type specimen. 



