HITCHCOCK AND CHASE TROPICAL NORTH AMERICAN PANICUM. 525 



108. Panicuiu albomaculatxim Scribn. 



Panicum albomaculatum Scribn. U. S. Dept. Agr. Div. Agrost. Circ. 19: 2. 1900; 

 Contr. U. S. Nat. Herb. 15: 311. 1910. 



Autumnal form leaning or ascending, with geniculate nodes, branching from the 

 lower and middle nodes, the branches nearly as long as the primary culm, erect, 

 simple or sparingly branching, the sheaths overlapping, the blades scarcely reduced, 

 the panicles short-exserted ; apparently no winter rosette developed. 



One specimen, Hitchcock 6979, has hai'shly pilose foliage, but in all other respects its 

 characters are those of P. albomaculatum. 



DISTRIBUTION. 



Shady banks and wooded slopes, 

 Mexico and Guatemala. The type 

 specimen from Pd.tzcuaro. 



Jalisco: ZapotMn, fizte^cocfe 7170, 



Amer. Gr. Nat. Herb. 193. 

 MichoacIn: Pdtzcuaro, Pringle 



5203. Uru^pan, Hitchcock 



6979. Jorullo, Humboldt 



OVilld. Herb.). 

 Guatemala: Antigua, Hitchcock 9139. 



Fig. 134.— Distribution of P. albomaculatum. 



GORDO VENSIA. 



Plants perennial, straggling, the culms decumbent at base, rooting at the nodes; 

 ligules membranaceous, minute; spikelets elliptical, the first glume two-thirds the 

 length of the spikelet or more; fruit smooth and shining, apiculate. 



Tliis group, to which are apparently allied the South American Panicum phragmites 

 Nees (P. discolor Triu., not Spreng.) and P. ovuliferum Trin., appeal's to be inter- 

 mediate between true Panicum and the subgenus DichantheUum, having the sterile 

 primary panicles and secondary panicles with fruitful, probably cleistogamous, 

 spikelets, but not forming a winter rosette. 



Plants glabrous or the leaves sparsely pilose 109. P. cordovense. 



Plants velvety pubescent, 110. P. chiriquiense. 



109. Panicum. cordovense Foum. 



Panicum cordovense Foum. Mex. PL 2: 26. 1886. "Cordova (Schaffn. n. 293 in 

 herb. Franq.)." The type specimen in the herbarium of Drake de Castillo, now a 

 part of the herbarium of the Jardin des Plantes, Paris, has glabrous spikelets (like 

 that shown in Fig. 135). This in the Revision was listed among the doubtful species. ^ 



Panicum expansum Foum. Mex. PI. 2: 26. 1886 (following P. cordovense). "Huita- 

 malco (Licbm. n. 426)." The type specimen, in the Copenhagen Herbarium, has a 

 large immature primary panicle, the spikelets glabrous. In the Revision ^ it was 

 suggested that this unknoNvn species was related to P. costaricense. 



Ichnanthus apicvlatu^ Scribn. U. S. Dept. Agr. Div. Agrost. Circ. 30: 1. 1901. 

 "Type specimen from near Jalapa, State of Vera Cruz. C. G. Pringle, no. 9208." In 

 the type specimen, in the United States National Herbarium, the spikelets are 

 glabrous. 



Panicum missionum Ekman, Ark. for Bot. 11*: 19. pi. 3. f.l. 1912. "Bonpland, 

 ad rivulum prope praedium 'Almac^n finlandesa,' 26. 12. 07. N. 632.", collected by 

 E. L. Ekman, in the State of Misiones, Argentina. An immature specimen of the 

 type collection is in the U. S. National Herbarium, received from Dr. Ekman. The 



» Contr. U. S. Nat. Herb. 15: 329. 1910. 

 2 Contr. U. S. Nat. Herb. 15: 134. 1910. 



