508 



CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Fig. 94. — Distribution of P. cyanescens. 



DISTRIBUTION. 



Swamps and wet eavannas, Britifih 

 Honduras and Trinidad to Brazil. 



British Honduras : Manatee La^ 

 goon, Pech 271 (Gray Herb.). 



Trinidad : Piarco Savanna, Hitch- 

 cock 10349, 10354, 10364. Cu- 

 muto Station, Eitchcockl00Q7 . 

 Aripo Savanna, Broadway 

 2377. 



UNGROTJPED SPECIES OP TRUE PANICTJM. 

 71. Panicum pyrularinm. sp. nov. 



Plants annual; culms delicate, 10 to 13 cm. high, at first erect and simple, finally- 

 decumbent and branching, often rooting at the nodes, more or less zigzag, sometimes 

 elongating to 25 or 30 cm.; nodes sparsely pilose or glabrous; sheaths shorter than the 

 blades, glabrous or sparsely pilose; Ugule membranaceous, about 0.5 mm. long; blades 

 thin, flat, spreading, 1 to 3 cm.' long, 2 to 7 mm. wide (the lower sometimes smaller), 

 narrowly elliptical, somewhat clasping at base, obtuse or acutish at the apex, scabrous 

 on the margins, glabrous or sparsely pilose on both surfaces, sometimes glaucous; 

 panicles terminating the culm and branches, loose and open, 2 to 5 

 cm. long, about as wide, oval or pyramidal in outline, the delicate 

 flexuous branches and branchlets spreading or reflexed, smooth, 

 the capillary divaricate pedicels several times longer than the 

 spikelets; spikelets 1.5 mm. long, 0.6 mm. wide, turgid, pyriform, 

 long-attenuate at base, glabrous; first glume about half as long as 

 the spikelet, acute; second glume and sterile lemma 5-nerved, not 

 exceeding the fruit, the glume slightly shorter than the sterile 

 lemma; fruit 1 mm. long, 0.5 mm. wide, turgid. 



Type in the U. S. National Herbarium, no. 715639, collected 

 between Hato del Jobo and Cerro Vaca, eastern Chiriqui, Panama, altitude 700 to 

 1,000 meters, December 25 to 28, 1911, by H. Pittier (no. 5416). 



Panicum pyrularium, one of the smallest and most delicate species in the genus, ia 

 not related to any North American species. 



The South American Panicum polycomum Trin. is an allied species of more tufted 

 habit, with much narrower blades, smaller panicles, and smaller pubescent spikeleta 

 not attenuate at base. 



None of the labels with the specimens cited below indicates the habitat. 



DISTRIBUTION. 



Panama to Venezuela. 



Panama: Between Hato deljobo 

 and Cerro Vaca, Chiriqui, 

 Pittier 5416. 



Venezuela: To\aj[,Fendler2502. 



Colombia: Santa Marta, Smith 

 2570. Without locality, Tri- 

 ana 281 (2811?). 



Fig. 95.— p. pyrvy 

 larium. From 

 type specimen. 



\t\ f^ 



