134 



CONTRIBUTIONS PROM THE NATIONAL HERBARIUM. 



KEY TO THE SPECIES. 



Ligule a dense line of s ti '*f yellowish hxirs; plants perennial. 



Fruit about 2.5 mm. Ions?. Awn of .sterile lemma less than 2 mm. long. 



1. E. pyramidalis. 

 Fruit about 4 mm. long. 



Awn of sterile lemmx generally 5 to 10 mm. long; sterile floret staminate. 



2. E. polystachya. 

 Awn of sterile lemma generally 4 to 5 cm. long; sterile floret neuter. 



4. E. holciiormis. 

 Ligule wanting, the ligular area sometimes pubescent; plants annual. 

 Racemes simple, rather distant, 1 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. 



7. E. colonum. 

 Racemes more or less branched, usually more than 2 cm. long; spikelets irregularly 

 crowded and fascicled, usually not arranged in rows, the awn of the sterile 

 lemma variable; blades usually more than 5 mm. wide. — 



Fruit about 4 mm. long 3. E. oplismenoides. 



Fruit 2.5 to 3 mm. long. 

 Sheaths smooth; awns variable, but the panicle not a dense mass of long-awned 



spikelets 6. E. crusgalli. 



Sheaths, at least the lower, hispid or scabrous; panicle dense, the spikelets 

 long-awned 5. E. walteri. 



D. Rous- 



1. Ecbinochloa pyramidalis (Lam.) Hitchc. & Chase. 



Panicum pyramidale Lam. Tabl. Encycl. 1:171. 1791. "E Senegal, 

 sillon." 



Panicum spectabile var. guado- 

 loupense Hack. Notizbl. Bot. 

 Gart. Berlin 1: 328. 1897. 

 "Habitat in Guadeloupe in 

 fossis et locis aquaticis prope 

 faubourgs de la Pointe a Pitre: 

 Duss n. 3176." 



Echinochloa pyramidalis Hitchc 

 & Chase, Contr. U. S. Nat. Herb. 

 18: 345. 1917. Based on Pani- 

 cum pyramidale Lam. 



DESCRIPTION. 



Plants perennial; stems erect, 

 rather fleshy, 1.5 to 2.5 meters 

 tall, glabrous; sheaths glabrous; 

 ligule a dense row of stiff yellow- 

 ish hairs 1 to 2 mm. long; blades 

 40 to 60 cm. long, 5 to 10 mm. 

 wide, glabrous above, scabrous 

 on the margins and on the nerves 

 beneath; panicle 20 to 40 cm. 

 long, the axis scabrous; racemes 

 numerous, ascending, 2 to 7 cm. 

 long, single or somewhat fasci- 

 cled, distant below but overlap- 

 ping, stiffly pilose at base and 

 sparsely so al ing the scabrous or hispidulous rachis; spikelets about 3 mm. long, 

 rather loosely arranged along the rachis, scabrous or slightly hispidulous on the 



Fig. 25. — Echinochloa pyramidalis. From Duss 3175, Guadeloupe. 



