52 



CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



1. Cenchrus myosuroides H. B. K. 



Cenchrus myosuroides H. B. K. Nov. Gen. & Sp. 1 : 115. pi. 35. 1S16. Collected 

 by Humboldt and Bonpland on Flamingo Key, off the port of Batabano, Cuba. 

 The type specimen has not been examined, but the plate identifies the species. 



Panicum cenchroides Ell. Bot. S. C. & Ga. 1: 111. 1816. Not P. cenchroides 

 Rich. 1792. Collected by " Dr. Baldwin, who found it on Jekyl Island, Georgia." 

 The type specimen in the Elliott Herbarium consists of the upper part of a 

 culm with inflorescence. 



Pennisetum pungens Nutt. Gen. PI. 1 : 54. 1S18. Based on Panicum cen- 

 chroides Ell. 



Pennisetum myosuroides Spreng. Syst. Veg. 1 : 303. 1825. Based on Cen- 

 chrus myosuroides H. B. K. 



Cenchrus elliottii Kunth, Rev. Gram. 1 : 51. 1829. Based on Panicum cen- 

 chroides Ell. 



Cenchrus alopecuroides Presl, Rel. Haenk. 1 : 317. 1830. Not C. alopecuroides 

 Thunb. 1794. The type specimen was collected by Haenke, but the habitat 

 was unknown to Presl. It was probably from the coast of Peru. The type 

 was examined in the herbarium of the German University at Prague by A. S. 

 Hitchcock in 1907. No locality is given on the label. 



Cenchrus setoides Buckl. Prel. Rep. Geol. Agr. Surv. Tex. App. 3. 1866. 

 " Prairies, Northern Texas." The type specimen in the herbarium of the Acad- 

 emy of Natural Sciences, Philadelphia, consists of the upper parts of three 

 culms with spikes. The name on the ticket is a slightly different form from 

 that published. A second ticket reads " Texas, Linscum & Buckley.'" 



Cenchropsis myosuroides Nash in Small, Fl. Southeast. U. S. 109, 1327. 1903. 

 Based on Cenchrus myosuroides H. B. K. 



DESCRIPTION. 



Plants perennial, solitary or in small clumps, usually 1 to 2 meters tall, 

 glabrous as a whole ; culms rather robust and woody, terete, commonly glau- 

 cous, erect or geniculate below (rarely decumbent with ascending flowering 

 branches), commonly branching from the lower 2 to 5 nodes, most of the 

 branches sterile, sometimes fascicled, forming conspicuous knobs at the node; 

 sheaths loose, usually not clasping the internodes, firm, strongly nerved ; ligule 

 2 to 3 mm. long, firm-membranaceous, with a densely ciliate margin ; blades 



ascending or spreading, firm, 15 to 40 

 cm. long, 5 to 12 mm. wide, tapering 

 from the rounded flat base to an at- 

 tenuate, often involute tip, scabrous 

 on the upper surface, rarely sparsely 

 pilose at the base ; inflorescence usu- 

 ally short-exserted, 10 to 25 cm. long, 

 5 to 9 mm. wide, strict, erect, dense, 

 the common axis slender, angled, 

 puberulent ; burs 1-flowered, at first 

 appressed, spreading in age, 5 to 7 

 mm. (mostly about 5 mm.) long, at maturity about as wide, the bristles 

 retrorsely scabrous, united at the base only, the lowest row shorter, 

 slender and spreading, the inner bristles slender, not flattened nor nerved, 

 about equaling the spikelet, erect or nearly so; spikelet 4.5 to 5.5 mm. long, 1.5 

 to l.S mm. wide, acuminate ; first glume about one-third the length of the spike- 

 let ; second glume and sterile lemma 3 to 5-nerved, the glume slightly shorter 

 than the equal sterile lemma and fruit. 



Fig. 7. — Cenchrus myosuroides. 

 Le6n & Voisard 835, Cuba. 



From 



