HITCHCOCK AND CHASE — NORTH AMERICAN PANICUM. 



25 



DESCRIPTION. 



Fig. 3.— P. chapmani. From type 

 specimen. 



Plants cespitose, glabrous; culms ascending or spreading, 40 cm. to 1 meter high, 



slender, compressed, wiry, sparingly branching; sheaths about as long as the inter- 

 nodes, compressed, pubescent at the scarcely au- 

 riculate summit, sometimes cilia te on the margin; 

 ligule a ring of very short hairs; blades erect, 

 rather firm, linear, 15 to 40 cm. long, 2 to 5 mm. 

 wide, acuminate, narrowed to the base, more or 

 less involute when dry, scabrous on the margin 

 and upper surface, the latter usually sparsely pilose 

 toward the base; panicles elongated, sometimes 

 as much as 30 cm. long, of remote, appressed, 

 raceme-like branches bearing few to several sub- 

 sessile, somewhat crowded spikelets, the setiform 

 prolongation of the axis 3 to 6 mm. long; spikelets 



2 to 2.2 mm. long, 1 to 1.2 mm. wide, obovate, abruptly pointed, turgid, pale green 



or yellowish; first glume about one-third the length of the spikelet, obtuse or 



truncate, 3-nerved; second glume 



slightly shorter than the fruit and 



sterile lemma, strongly 5 to 7-nerved, 



obscurely reticulated; fruit 1.8 mm. 



long, 1 to 1.1 mm. wide, elliptic, 



abruptly acute, minutely rugose, the 



margins of the lemma inrolled only at 



base. 

 As observed on Key Largo the 



blades in this species are flat on plants 



growing in shaded situations and in- 



, " , . ,, „,. Fig. 4.— Distribution of P. chapmani. 



volute on plants in the sun. The 



flat blades become more or less involute in drying. 



DISTRIBUTION. 



Coral sand and shell mounds, southern Florida and the Bahamas. 

 Florida: Marco, Hitchcock Lee Co. PI. 487; Cape Sable, Simpson 157; Key 



Largo, Chase 3926, Curtiss 5457; Little Pine Key, Curtiss 3607; Key West, 



Garber in 1877; "Shores of Manettee River, "a Rugel 394; without locality, 



Blodgett, Chapman. 

 Bahamas: New Providence, Britton & Brace 401; Rose Island, Britton & Mills- 



paugh 2137; Great Exuma, Britton & Millspaugh 3076 (all in Field Mus. 



Herb.). 



4. Panicum ramisetum Scribn. 



Panicum subspicatum Vasey, U. S. Dept. Agr. Div. Bot. Bull. 8 : 25. 1889, not Desv. 

 1831. "Texas (Buckley, Nealley)." Both specimens cited by Vasey are in the 

 National Herbarium. The second of these has been chosen as the type for the following 

 reasons: The first specimen cited, S. B. Buckley in 1881, does not bear the specific 

 name in Vasey 's hand, and furthermore is a mixture of P. ramisetum and P. reverchoni; 

 the second specimen, collected in Texas by G. C. Nealley in 1887, bears the specific 

 name, "subspicatum V." in Vasey's hand. Another Nealley specimen bears the 

 name in Vasey's hand, but was collected in 1892, after the publication of the species. 



Panicum ramisetum Scribn. U. S. Dept. Agr. Div. Agrost. Circ. 27: 9. 1900. Based 

 on Panicum subspicatum Vasey, not Desv. 



a This locality, if meant for Manatee River, is probably an error. 



