162 PANIC ACEiE. 



tlic preceding, spikelets much snuiller, fertile floret 3 mm. long. 

 This corresponds witli the remark of Grisobuch in his Flora of the 

 West Indies, "All West Indian specimens agree in the small size 

 of the spikelet, while in the northern, original form, the si)ikelets 

 are usually twice as large; the species, however, is as varial)le as the 

 preceding (C ev/iinatiis L.) and often ditiicult to be distinguished 

 from it." 



A plant from Mobile, Ala., sent by Dr. C. Mohr, is no doubt 

 C. incertus Curtiss. The second glume is 6-nerved, third glume 

 or paleaof the lower floret contains astaminate flower. Most likely 

 C inecrtun Curtiss. also C. paucijlorus Benth., should be included 

 in the al)()ve variable s})ecies. 



A troublesome weed on sandy lands found from Xew England 

 to California, West Indies, ]\[exieo. Brazil, Africa, East Indies. 



5. C. Palmeri Vasey, Proc. Cal. Acad. (II.) '^: 211 (188!»). 



Annual; culms rather slender, geniculate, branching, about 30 

 cm. high. Sheaths loose, about as long as the intcrnodes; ligule 

 hairy; blades numerous, rough, flat, 10. cm. long, 5-8 mm. wide. 

 Peduncles exserted, bearing 2-3 twinlike downy burs 2 cm. long, 

 including the stout spines before they are bent and hardened, 

 each bur including 5-7 spikelets. Sj)ikelers ovoid, acute. 

 mm. or more long; flrst and second glumes alike, ovate-cuneate, 

 obtuse, truncate or irregularly divided with o strong green nerves; 

 palea of the staminate flower about the length and shape of the 

 empty glumes. 2-nerved; floral glume of the fertile floret oval, 

 as long as the empty glumes, acuminate with 7 ])rominent nerves, 

 its palea with 2 strong nerves. When mature the burs are often 

 3 cm. diam. from the tips of the stout spines. Spines yellow or 

 black. 



Lower California, Palmer 089: Mexico, Pdhner 271. 



Abundant on sandy bottoms, where it must be a formidable 

 nuisance to man and beast. 



32. (1-4). Pennisetum IJich. Pers. Syn. 1: 72 (1805). Peni- 

 cillaria Wild. Euum. Ilort. l^erol. 1036 (1809). Gi/nniothrix 

 Beauv. Agrost. 59. /. 13, f. C, (1812). ('atathcroplun-a Steud. 

 Flora, 12:465 (1829). PentastacJnja llochst. Steud. Noni. Ed. 3, 



