526 



COISTTEIBUTIONS FEOM THE NATIONAL HEEBAEIUM. 



cordovensc. From 



TlUchcodt 8328. 



photograph of the type specimen (plate 3, figure 1) shows the large open primary 

 panicle, like that of the type of P. expansum, which is characteristic of the early 

 phase of the species. 



DESCRIPTION. 



Plants perennial in tangled masses; culms slender, subcompressed, a line of pubes- 

 cence down one side or glabrous, rarely sparsely pilose, straggling, widely creeping, 

 rooting at the lower nodes, as much as 2 meters long, freely branching, the branches 



usually divergent, becoming nearly as long as the 

 primary culm; nodes puberal ent or glabrate; sheaths 

 much shorter than the usually elongate intemodes, 

 sparsely papillose-pilose or papillose only, densely 

 ciliate on the margin, puberulent at the junction with 

 the blade; ligule about 0.3 mm. long; blades thitij 

 fiat, spreading, 5 to 10 cm. (rarely as much as 15 

 cm.) long, 5 to 10 mm. wide, narrowly lanceolate, 

 acuminate, rounded and usually ciUate at base, scab- 

 erulous on both sm"faces at least on the midnerve, 

 usually papillose-hispid above the ligule, sometimes 

 sparsely so throughout; panicles of two kinds, the 

 primary short-exserted or included at base, loose and 

 open, 10 to 15 cm. long, half to two-thirds as wide, the axis and branches slender, sub- 

 flexuous, scaberulous, pubescent in the axils, the few branches solitaiy or in pairs, 

 remote, simple or nearly so, finally spreading, few-flowered, the branchlets and short- 

 pediceled, apparently unfruitful spikelets more or less appressed to the rachis, the 

 secondary panicles terminal on the branches, 

 reduced, narrow, few-flowered, partially 

 inclosed in the sheath, the crowded appai-- 

 ently cleistogamous spikelets fruitful ; spike- 

 lets 3 to 3.5 mm. long, 1.2 to 1.4 mm. wide, 

 those of the primary panicles usually glab- 

 rous, those of the secondary panicles usually 

 pustulose-villous, turgid; first glume about 

 two-thirds as long as the spikelet, obtuse, 

 3 to 5-nerved, the second glume and sterile 

 lemma equal, covering the fruit, 7-nerved, 

 the middle intemerves of the sterile lemma 

 in the pubescent spikelets usually glab- 

 rous, the midnerve sometimes indistinct; fruit 2.8 to 2.9 mm. long, 1.1 to 1.2 mm. 

 wide, apiculate. 



The spikelets shown in figures 135 and 136 are from the terminal and lateral panicles 

 respectively of the same individual. 



DISTRIBUTION. 



Shady banks and in deep woods, southern Mexico to Argentina. 



Fig. 136.— p. cordovense. From HiicJicock 8328. 



Fig. 137.— Distribution of P. cordovense. 



Veracruz: Cordoba, Schaffner 293. 

 Jalapa, Pringle 9208, Hitchcock 

 6611. Huitmalco, Liebmann 

 426. 



Costa Rica: Piedra del Convento, 

 Pittier 3655. 



Panama: Chiriqui Volcano, Hitch- 

 cock 8196. El Boquete, Hitch- 

 cock 8271, 8275, 8303, 8328. 



