250 



CONTKIBUTIONS FKOM THE NATIONAL HEEBABIUM. 



Autumnal form prostrate, forming mats, with short, fascicled branches at all the nodes, 

 the branches appearing before the maturity of the primary panicles; leaves and 

 panicles not greatly reduced, the latter overtopped by the blades, which are less pilose 

 than earlier ones; winter blades sparsely pilose above. 



This species is more copiously pubescent than any other in this group and in this 

 character resembles species of the Lanuginosa, but its affinity seems to be rather 

 with the Columbiana. 



DISTRIBUTION. 



Sand barrens along the coast, Massachusetts to Virginia. 

 Massachusetts: Nantucket, Bartlett 1368, 1379, Bicknell in 1906, Hitchcock 558; 



Plymouth, Oakes; Quanquisset, Bartlett 1327. 

 Connecticut: Groton, Bissell 9306 



(Bissell Herb.). 

 New York: North ville, Young in 



1871 ; West Rockaway, Bicknell 



in 1903; Lawrence, Bicknell 



in 1906; Hempstead, Bicknell 



in 1903; Woodmere, Bicknell 



in 1902; Rockville Center, 



Bicknell in 1906; Valley 



Stream, Bicknell in 1905. 

 New Jersey: Absecum, Commons 



45; Tuckerton, Chase 3609; 



East Plains, Stone 8; Atlantic 



City, Parker; Hammonton, Canby in 1902; South Amboy, Mackenzie 1355; 



Atsion, Chase 3562; Toms River, Chase 3576; Forked River, Chase 3581. 

 Delaware: Rehoboth, Commons 59, 60; Lewes, Hitchcock 47 '. 

 Virginia: Ocean View, Coville 13, 14, Kearney 1461; Cape Henry, Chase 5431. 



Sphaerocarpa. — Culms usually few in a tuft, rather stout, glabrous; ligules obsolete 

 or nearly so; blades mostly thick and firm, cordate and ciliate at base, mar- 

 gins strongly cartilaginous; spikelets obovoid-spherical at maturity, oval 

 when young, 1 to 1.8 mm. long, puberulent; second glume and sterile lemma 

 5 to 7-nerved; panicle branches mostly viscid. Autumnal form remaining 

 simple or but sparingly branching, the thick, white-margined blades of the 

 winter rosette conspicuous. 

 Culms spreading; blades obscurely nerved; panicle nearly as broad as long. 



Ligules obsolete or wanting; blades lanceolate 149. P. sphaerocarpon. 



Ligules evident, 0.3 to 1 mm. long; margins of blades 



parallel for at least two-thirds their length 149a 



Fig. 272.— Distribution of P. oricola. 



P. 



Culms erect or ascending; blades rather strongly nerved; 

 panicle never more than two-thirds as broad as long, 

 usually less. 

 Spikelets 1.5 to 1.6 mm. long; blades lanceolate, the 



upper not reduced 150. 



Spikelets 1 to 1.2 mm. long; blades tapering from base to 



apex, the upper much smaller than the lower 151. 



sphaerocarpon 

 inflatum. 



P. polyanthes. 

 P. erectifolium. 



