HITCHCOCK AND CHASE — NORTH AMERICAN PANICUM. 



33 



Type U. S. National Herbarium no. 207685, collected May 16 to 31, 1894, "in water," 

 in the vicinity of Eusjis, Lake County, Florida, by George V. Nash (no. 746). 



This species differs from P. geminatum in the succulent stems, the lower part 

 submerged, branching and rooting at the nodes, the loose papery sheaths, the lower 

 nearly bladeless, the elongated aerial blades, and the longer, not turgid spikelets, 

 scarcely nerved glumes, shorter second glume, and nearly smooth fruit. 



This species has usually been distributed as Panicum paspalodes Pers. It is closely 

 related to the species described by Hooker as P. punctatum Burm.a but differs espe- 

 cially in the papery, nearly nerveless glumes and sterile lemma and the nearly 

 smooth fruit. 



The preceding species, P. geminatum, grows along the seacoast, while this species 

 appears to be an inhabitant of fresh- water lakes and rivers. Lake Amatitlan, the cited 

 locality for the Guatemala specimens, lies at an altitude of 1,200 meters. Pringle's 

 no. 9556 is labeled "In water, Valley of Zamora, 5000 ft.," and his no, 3336, "Shallows 

 of Lake Patzcuaro." 



DISTRIBUTION. 



Growing more or less submerged in fresh-water rivers and lakes of the interior at 

 least up to 1,600 meters altitude, in Florida, Texas, Mexico, and Central America; also 

 in Uruguay. 



Florida: Grasmere, Combs 760, 

 1052; Eustis, Nash 746; Man- 

 atee, Tracy 7412; Braiden- 

 town, Combs 1253; Little 

 River, Garber in 1877. 



Texas : Without locality, Nealley 

 in 1888. 



Mexico : Guadalajara, Palmer 429 

 in 1886; State of Michoacan, 

 Valley of Zamora, Pringle 

 9556; Lake Patzcuaro, Prin- 

 gle 3336. 



Guatemala: Amatitlan, Tuerckheim 8790; Lake Amatitlan, Kellerman 6253, 6254, 

 Pittier 101. 



Uruguay: Montevideo, Arechavaleta. 



9. Panicum barbinode Trin. 



Panicum purpurascens Raddi, Agrost. Bras. 47. 1823, not H. B. K. 1815. Raddi 

 states that this species is cultivated "in Provincia Rio Janeiro," and also grows spon- 

 taneously. We have not seen the type, but Raddi's description applies well to P. 

 barbinode. 



Panicum barbinode Trin. Mem. Acad. St. Petersb. VI. Sci. Nat. 1:256. 1834. 

 Trinius cites "Panicum barbinode Trin. ic. gr. XXVII. tab. 318," then unpublished, 

 and states that his specimen is from Brazil. In the Icones & the habitat is given as 

 Bahia. This specimen, in the Trinius Herbarium, which is the type, is labeled 

 "Bahia, Riedel 1831." 



Panicum guadaloupense Steud. Syn. PI. Glum. 1: 61. 1854. "Ins. Guadaloupe." 

 We have not seen the type, but the description applies well to P. barbinode Trin. 



Panicum equinum Salzm.; Steud. Syn. PL Glum. 1: 67. 1854. "Salzmann in 

 Bahia "is the first specimen cited. The specimen in the De Candolle Herbarium 

 labeled "P. equinum Salz., Bahia, Salzm." is probably the type. 



a See footnote d, page 31, [P. geminatum] and the paragraph to which it is appended. 

 & Gram. Icon. 3 : pi. 318. 1836. 



41616°— vol 15—10 3 



Fig. 14.— Distribution of P. paludivagum. 



