Hitchcock — The Grasses of Hazcaii 203 



margins inrolled below, flat above, the apex of the palea not inclosed. Coarse, often succulent, 

 annual or perennial, grasses, with compressed sheaths, linear flat blades, and rather compact 

 panicles composed of short, densely flowered racemes along a main axis. 

 Racemes without stiff hairs at base, simple, rather distant, i to 2 cm. long; spikelets crowded 



in about 4 rows, the awn of the sterile lemma reduced to a short point ; blades 3 to 6 mm. 



wide I. E. colonum. 



Racemes hispid at base with long stiff hairs, more or less branched, commonly more than 2 cm. 



long; spikelets irregularly crowded and fascicled, not arranged in rows, the awn of the 



sterile lemma more or less developed ; blades commonly more than 5 mm. wide 



- 2. E. crusgalli crus-pavonis. 



1. Echinochloa colonum (L.) Link, Hort. Berol. 2:209. 1833. 



Panicum coloiuiin L. Syst. Nat. ed. 10. 2:870. 1759. 



Plants annual ; culms prostrate-spreading, ascending, or erect, commonly 20 to 40 cm. 

 long, glabrous, compressed; sheaths glabrous, compressed; ligule wanting; blades rather lax, 

 5 to 10 cm. long, rarely longer, 3 to 6 mm. or rarely as much as i cm. wide, somewhat scab- 

 rous on the margins, occasionally with transverse purple bands (zonate) ; panicles 5 to 

 10 or even 15 cm. long, the axis smooth or slightly scabrous; racemes several, i to 2 cm. long or 

 rarely longer, appressed or ascending, single or two approximate, the lower ordinarily 

 distant as much as i cm., the rachis triangular-flattened, scabrous ; spikelets about 3 mm. long, 

 crowded, nearly sessile, in about 4 rows ; second glume and sterile lemma short-pointed but not 

 awned; fruit about 2.5 mm. long, short-pointed (fig. 94). 



Along streets and in fields ; introduced. Originally described from India. 

 Oahu: Honolulu, Hitchcock 13709, 13746; Munro 7. Waialua Alountains, ]\Iann 



& Brigham 268. JNIakiki, Heller 1978. 

 Hawaii: Hilo, Newell in 1917. 



2. Echinochloa crusgalli crus-pavonis (H. B. K.) Hitchc. Contr. U. S. Nat. Herb. 22:148. 1920. 



Oplisiiiciius cnis-pazviiis H. B. K. Nov. Gen. & Sp. i :io8. 1816. 



Plants annual ; culms erect or sometimes decumbent at base, as much as i meter or even 

 1.5 meters tall, glabrous; sheaths glabrous; ligule wanting, the ligular area sometimes slightly 

 pubescent; blades 2 to 8 mm. wide, sometimes wider, scabrous on the margins, sometimes on 

 the upper surface ; panicles nodding, rather soft, 10 to 20 cm. long, the axis scabrous ; racemes 

 mostly ascending or appressed, the lower somewhat distant, as much as 10 cm. long but as a 

 rule shorter, commonly unbranched, the upper approximate, shorter, the rachis scabrous, hispid, 

 especially at the base ; spikelets crowded, about 2.3 mm. long, excluding the awns, strongly 

 hispid or papillose-hispid on the nerves, hispidulous on the internerves ; sterile lemma with a 

 well-developed palea, neuter, the awn variable in length, mostly 5 to 10 mm. long, on at least 

 a part of the spikelets, sometimes as much as 3 cm. long; fruit elliptic, turgid, narrowed into 

 a cusp or point, about 2 mm. long, whitish or brownish (fig. 95). 



This variety of the cosmopolitan E. cnisgalli is common in tropical America. 

 It differs from the species itself in having nodding rather soft panicles, the spike- 

 lets averaging smaller, less strongly hispid, the awn variable in length, but as a 

 rule not over i cm. long. Awned and awnless or partially awnless panicles may 

 occur on the same plant. In some plants only the spikelets near the end of the 

 raceme are awned. In Hitchcock's 14462, Waimea, Hawaii, the sterile lemmas 

 are indurate like the fertile. This specimen has awnless, rather larger spikelets, 

 and possibly might better be referred to B. crusgalli c:clayeiisis (H. B. K.) Hitchc. 

 of Mexico. 



Along ditches and especially in rice fields ; introduced. Originally described 

 from Venezuela. 



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