Hifclicock — The Grasses of Hawaii 211 



1. Cenchrus agrimonioides Trin. Gram. Pan. /2. 1826. 



Ccuclirus calyciilatiis iiiiiflonis riillel)r. Fl. Haw. Isl. 505. 1888. 



Plants perennial, very leafy : culni.s glabrou.s, scabrous below the panicle, robust, swollen 

 at the nodes, 30 to 60 cm. tall, the internodes short : sheaths compressed-keeled, much longer 

 than the internodes, glabrous; blades flat or folded, 15 to 30 cm. long, 4 to 8 mm. wide, glabrous 

 beneath, scabrous on the upper surface: racemes 5 to 10 cm. long, the axis densely puberulent; 

 burs approximate, mostly somewhat reflexed at maturity, fusiform, about i cm. long, the base 

 narrow below, expanding above, 2 to 3 mm. long, densely pubescent; basal series 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, densely tomentose along the middle part, the apex 

 retrorselv scabrous; spikelets i in each bur (tig. 104). 



The Laysan specimens have somewhat larger burs and flat blades 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: ^^'ithout locality, ^\'ilder in 1912. 

 Lanai : Munro 404. 



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

 Withottt locality: Hillebrand; \\'awra. 



2. Cenchrus echinatus L. Sp. PI. 1030. 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, scabrous 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). 



Weed in. fields; introduced. Apparently rare in the Hawaiian islands; com- 

 mon in the American tropics. Originally described from 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, 

 flexuous, 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 about as the second glume, minutely 



L113] 



