54 



CONTRIBUTIONS FROM THE NATIONAL. HERBARIUM. 



of the Montpellier garden, and in the author index in Linnaea Delile is given 

 for page 102, where the article on the Index Monspeliensis begins. Through 

 the kindness of Dr. Granel, director of the Jardin des Plantes, Montpellier, we 

 have received two specimens of Cenchrus catharticus from the Delile Herba- 

 rium. These are labeled, " In hort. Monspel. cult, anno 1842," hence are not 

 part of the type material, which may not have been preserved, but serve to 

 identify the species without doubt. 



Cenchrus niloticus Fig. & DeNot. Mem. Accad. Sci. Torino 14: 380. pi. S3. 

 1852. Described from Nubia. The detailed description and the plate identify 

 the species. 



Cenchrus annularis Anderss. in Peters, Eeise Mossamb. Bot. 553. 1864. De- 

 scriBed from Mozambique. The description identifies the species. 



DESCRIPTION. 



Plants annual, glabrous as a whole, decumbent and rooting at the lower 

 nodes, the ends and the branches ascending; culms 30 to 100 cm. long, not much 

 compressed, scabrous below the inflorescence ; sheaths loose, keeled, scabrous 

 at the summit; ligule stiffly ciliate, about 1 mm. long; blades narrowly ascend- 

 ing, 10 to 20 cm. long, 5 to 6 mm. wide at the base, tapering thence to an 

 attenuate involute tip, scabrous on the upper surface, smooth or nearly so 

 beneath ; spikes included at base or short-exserted, 8 to 10 cm. long, about 



7 to 9 mm. wide, the axis slender, angled, 

 scabrous ; burs usually 2-flowered, nearly 

 erect, 4 to 6 mm. long, scarcely as wide, the 

 pedicel almost obsolete ; bristles united at 

 the base only, the outer row short, terete, 

 spreading, unequal, the inner (7 to 10) flat- 

 tened, subequal, rigid, erect, the scabrous 

 tips slightly spreading, the outer surface 

 sulcate down the middle, with 1 to 3 green 

 nerves in the sulcus, densely villous along 

 the margin on the inner surface except at 

 the summit; spikelets slightly shorter than the inner involucral lobes; first 

 glume developed or obsolete, second glume and sterile lemma thin, faintly 3 to 

 7-nerved, two-thirds to three-fourths as long as the fruit, the sterile palea usually 

 well developed ; fruit 4 to 4.5 mm. long, about 1.5 mm. wide, acuminate. 



Known in America only from ballast about Mobile, Alabama; several speci- 

 mens collected in 1891 and 1892 by Dr. Charles Mohr. Our plants agree with 

 the specimens from the Delile Herbarium and with Abyssinian specimens. In 

 the plant described in Hooker's Flora of British India 1 under the name of 

 Cenchrus catharticus the inner involucral bristles are longer, more sharply 

 pointed, and less rigid. 



3. Cenchrus distichophyllus Griseb. 



Cenchrus distichophyllus Griseb. Cat. PI. Cub. 234. 1866. "Cuba occ. 

 (Wr[ight] 3475)." The type specimen, collected by Wright in 1863, is in the 

 Grisebach Herbarium. It consists of a single fertile culm and a tuft of one 

 fertile and several sterile culms. 



DESCRIPTION. 



Plants perennial ; culms tufted, rigid, erect, or ascending from a curved, not 

 geniculate base, simple or with a few appressed branches, the numerous inter- 



3 



Fig. 8. — O enchru a catharticus. 

 From specimen from the Delile 

 Herbarium. 



>7: 90. 1896. 



