THE NORTH AMERICAN SPECIES OF PENNISETUM. 219 



5. Pennisetum karwinskyi Schrad. 



Ptnniselum karwinshji Schrad. Linnaea 12: 431. 1838. "Habit, in Mexico (Kar- 

 winsky)." In the Schrader Herbarium, which is preserved in the herbarium of the 

 BotanicaJ Garden at Petrograd, there are two sheets bearing this name, but no data. 

 On one sheet are leaves only; on the other is a culm with a single purplish panicle 

 about 5 cm. long. The fascicles of this panicle are smaller than usual for the specks 

 and the inner bristles are only sparsely short -ciliate. The description and the speci- 

 men represent a rather dwarfed plant such as Rose, Standley & Russell's no. 12866, 

 from Alamos, Sonora. 



Cenchrus multiflorus Presl, Rel. Haenk. 1: 318. 1830. "Hab. in Mexico." The 

 type specimen was examined by Professor Hitchcock in the herbarium of the German 

 University at Prag. The fascicles are much like those of Pringle's no. 3849. Most of 

 the bristles only slightly exceed the spikclets, the inner are more pilose than usual 

 for the species, and one bristle is about twice as long as the rest, thicker, and stiffly 

 fiexuous. 



Pennisetum multiflorum Fourn. Mex. PI. 2: 49. 1886. No locality or specimen is 

 cited. The description is as follows: "Spica imbrieata, spiculis quinis in eodem 

 involucre, quarum 1-2 abortientes; gluma inferiore tertiam partem spiculae aequante 

 superiore inferiorem duplam aequante; involucri setis ex.terioribus brevibus scabris; 

 interioribus crassioribus in dimidia tantum inferiore parte ciliatis, spiculas duplo 

 superantibus, seta una multo longiore." In the Copenhagen Herbarium is a speci- 

 men of Liebmann's no. 463 which bears the name "Pennisetum multiflorum Fourn." 

 in Fournier's handwriting. This consists of a single naked elongate terminal joint 

 and, in an envelope, a fragment, 5 cm. long, of a panicle, the fascicles with exception- 

 ally slender bristles, scarcely at all ciliate, the innemiost one as much as 3.5 cm. long 

 (as in Nelson's no. 3035) ; three fascicles with short subeq ual bristles, the inner sparsely 

 ciliate (as in Pringle's no. 2044); and a single bur of Cenchrus pilosus H. B. K. (the only 

 American species of Cenchrus known in which the bristles are antrorsely scabrous). 

 Since only the inflorescence is described, it Seems certain that Fournier's descrip- 

 tion was based on this fragmentary specimen. The allusion to the ciliate lower part 

 of the thickened inner bristles must have been made from observation of The bur of 

 the Cenchms. Fournier does not base the name on Cenchrus multiflorus Presl, though 

 he is naming the same species. He includes Cenchrus multiflorus Presl in Cench r us. 

 Liebmann's nos. 341 and 464, which he cites under it, are in the Copenhagen Her- 

 barium; no. 464 bears the name Cenchrus multiflorus in Fournier's hand, the other is 

 marked "determ: Fournier.'' Both are Pennisetum harwinshn . 



description. / 



Plants perennial, in loose clumps from hard knotted crowns, the culms produced 

 from hard scaly bulblike buds bursting through the basal and underground sheaths; 

 culms erect or ascending, simple or with leafy shoots from the lower nodes, mostly 

 1 to 1.5 meters tall, rarely only about 0.5 meter, very scabrous below the panicle, other- 

 wise glabrous, the lower internodes compressed; sheaths keeled, mostly overlapping, 

 pilose along the margin at least toward the summit, sometimes sparsely papilkse- 

 pilose, or rarely the lower densely pilose, throughout; ligule 1.5 to 2 mm. long, mem- 

 branaceous-ciliate; blades usually rather firm, ascending or spreading, flat, 10 to 40 

 cm. long, 5 to 15 mm. wide, broadest at the base, tapering to a long, attenuate, very 

 scabrous, usually involute tip, the upper surface scabrous and usually sparsely papil- 

 lose-pilose, rarely densely so, sometimes scabrous only, the lower surface usually 

 scabrous, sometimes smooth, the margins very scabrous; panicle rather stiff or slightly 

 fiexuous, 5 to 17 cm. long, mostly 10 to 12 mm wide, excluding the longest bristles, 

 tawny or purplish or sometimes greenish, mostly dense except at the base, but 

 sometimes the fascicles rather loosely arranged, the axis strongly angled, pubescent; 



