1 1 ilcJiciH'k — The (irnxscs nf flcva'uii 



211 



1. Cenchrus agrimonioides 'I'lin. Gram. I 'an. 72. 1826. 



CciiclirKS calyciilatiis iiiiillonis llilk'lir. I''l. I law. Kl. 503. 1S88. 



I'laiits perennial, very leafy; culms L;iai)ruu.s, scaiirous below the ])anicle. robu.st. .swollen 

 at the nodes, 30 to 60 cm. tall, the internodes short: sheaths compressed-keeled, nnich lons^er 

 than the internodes, i;labrous : blades Hat <ir folded, 15 to 30 cm. long', 4 to 8 mm. wide, glabrous 

 beneath, scabrous on the tipper surface: racemes 5 to 10 cm. long, the a.xis densely puberulent ; 

 bur.s approximate, mostly somewhat reHexed at maturity, fu.siform, alxnit i cm. long, the base 

 narrow below, expanding above, 2 to 3 mm. long, den.sely pubescent; basal serie.s of bristles 

 numerous, more or less spreading, 2 to 3 mm. long, retrorsely .scabrous, the larger ones tomentu- 

 lose at base: body of bur cleft only one-third to scarcely one-half its length, lobes erect, 

 appressed, forming an irregular beak, densel\- tomentose along the middle part, the apex 

 retrorsely scabrous: spikelets 1 in each bur (fig. 104). 



The Laysan specimens have somewhat larger burs and flat bhides 15 to 

 20 cm. long and i to 2 cm. wide, and the base of the bur is more abruptly enlarged 

 upward. These may represent a distinct species. The specimens are said to be 

 3 or 4 feet tall. 



Originally described from the Hawaiian islands. 

 Laysan: Bryan 8729; Snyder in 1902. 

 Oahu: Without locality, \\'ilder in 1912. 

 Lanai : Munro 404. 



Maui : Auwahi, Rock. East Maui, Wilkes Expl. Exped. 

 Without locality: Hillebrand; Wawra. 



2. Cenchrus echinatus L. Sp. PI. 1050. 1753. 



Plants annual; culms much branched, decumbent at base, 30 to 50 cm. tall, scabrous below 

 the inflorescence; sheaths glabrous: blades flat, 5 to 10 cm. long, about 5 mm. wide, glabrous 

 beneath, scalirous on the upper surface : racemes 3 to 5 cm. long ; the axis scabrous on the 

 angles, the burs rather loosely arranged, barely touching each other ; burs globular, about 5 mm. 

 wide, the obconical base about i mm. long, tomentulose, the basal series of bristles 2 to 3 mm. 

 long, the inner series flattened, ascending or the innermost connivent below the middle, tomen- 

 tose except the apex; spikelets usually 3 or 4 in each bur (fig. 103 I. 



W'eed in. fields; introduced. Apparently rare in the Hawaiian islands; com- 

 mon in the American tropics. Originally described front Jamaica. 

 Oahu: Honolulu, Hitchcock 13854. 

 Hawaii: Hilo, Newell in 1917. 



3. Cenchrus hillebrandianus sp. nov. 



Plants annual, usually much branched and decumbent at base : culms glabrous, 30 to 

 50 cm. tall ; sheaths and blades soft-pubescent or villous, the sheaths mostly longer than the 

 internodes, compressed-keeled; the blades flat, ascending or spreading, mostly 10 to 15 cm. long, 

 3 to 6 mm. wide ; racemes mostly 3 to 6 cm. long, oblong, the axis angled, scabrous and pilose, 

 tlexuous, the internodes 2 to 3 mm. or the lower sometimes 5 to 8 mm. long ; burs globular, 

 mostly 5 to 6 mm. wide, the base villous, obconical, about 2 mm. long; outer series of spines 

 numerous, irregular in length, the longer about 3 mm. long; inner series stout, flattened below 

 and subulate above, about 5 mm. long, spreading or ascending, or the innermost incurved 

 villous except the tip; spikelets mostly 3 or 4 in each bur, about 6 mm. long: first glume triangu- 

 lar-ovate, broad, about 2 mm. long, i-nerved; second glume minutely scaberulous. about two- 

 thirds as long as the spikelet, strongly 3-nerved with 2 outer weaker pairs of nerves ; sterile 

 lemma acuminate, a little shorter than the fertile, nerved alwut as the second glume, minutely 



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