242 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



1/ 143. Panicum commonsianum Ashe. 



Panicum commonsianum, Ashe, Journ. Elisha Mitchell Soc. 15: 55. 1898. "Based 

 on no. 341, Commons. Collected in drifting sands along the coast, Cape May, N. J., 

 June, 1898." The type, in Ashe's herbarium, "Ex. Herb. A. Commons," consifits of 

 five tufts of vernal culms with mature primary panicles. 



DESCRIPTION. 



Fig. 259. — P. commonsianuw . From 

 type specimen. 



Vernal plants grayish olive, drying brownish; culms usually in dense tufts 20 to 50 

 cm. high, stiffly ascending or spreading, papillose-strigose to appressed-pilose, the hairs 

 at the nodes more spreading; sheaths shorter than the internodes, strigose to appressed- 

 pilose like the culms but less densely so; ligules 1 mm. long or less; blades firm, 



stiffly ascending, 5 to 8 (rarely 9) cm. long, 4 to 7 

 mm. wide, broadest near the rounded base, the ser- 

 rulate, cartUaginous margin involute toward the 

 acuminate apex, glabrous on the upper surface or 

 with a few long hairs toward the base or margin, 

 strigose on the lower surface or glabrous; panicles 

 long-exserted, 4 to 8 cm. long, about as wide, 

 loosely flowered, the axie and branches strigose 

 to nearly glabrous, the branches stiffly spreading, 

 spikelet-bearing toward the ends; spikelets 2.2 to 

 2.4 mm. long, 1.2 mm. wide, elliptic, subacute, 

 pubescent; first glume about half as long as the 

 spikelet, sometimes longer, usually pointed, 3-nerved; second glume slightly shorter 

 than the fruit and sterile lemma at maturity; fruit 2 mm. long, 1 mm. wide, elliptic, 

 subacute. 



Autumnal culms branching from the middle and upper nodes, after the maturity 

 of the primary panicles becoming spreading or prostrate, the larger clumps forming 

 mats in the sand, the reduced secondary subinvolute blades rather crowded, stiffly 

 ascending, overtopping the panicles; 

 winter blades lanceolate, commonly 

 more hairy than those of the culm. 



This species is variable as to pubes- 

 cence. 



DISTRIBUTION. 



Dunes and sandy woods near the 



coast, Connecticut to northern Florida. 



Connecticut: North Haven, An- 



dreios in 1901; South Windsor, 



Bissell 12000. 



New York: Lake Roukonkoma, 



Bicknell; Rockville Center, BicJcnell in 1906; Valley Stream, BicJcnell in 1905; 

 Hempstead, Bicknell in 1903. 

 New Jersey: South Amboy, Mackenzie 1485, 2155, 2165; East Plains, Stone 

 4, 6; Lakehurst, Mackenzie 2067; Toms ^iver, Bicknell in 1900, Chase 3575; 

 Forked River, Chase 3584, 3596; Atsion, Chase 3531, 3541, 3544, 3570; Cape 

 ■ May, Canhy 4 in 1902, Commons 43, 341; Wildwood, Chase 3517^ 

 Delaware: Lewes, Hitchcock Ad^, 



Fig. 260. — Distribution of P. commonsianum. 



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