NAIADACEA, 44] 
2. POTAMOGETON. 
Potamogeton, Linn. Gen. Plant. n. 174; Benth. et Hook. Gen. Plant. iii. p. 1014. 
Bentham and Hooker estimate the number of species at about fifty, independently of 
many subspecies and varieties regarded as species by other botanists. The genus is 
_ diffused throughout Temperate regions, and less commonly in the Tropics. 
1. Potamogeton angustissimum, H. B. K. Nov. Gen. et Sp. i. p. 370 ; Kunth, 
Enum. Pl. iii. p. 138. 
Souta Mexico, between the Puerto de Andaracuas and Valladolid, Michoacan at 
5500 feet (Humboldt & Bonpland). 
There is a Mexican specimen in the Kew Herbarium, collected by Schaffner, and 
named P. angustifolium, H. B. K., by him, which may be this species. 
2. Potamogeton hybridus, Michx. Fl. Am.-Bor. i. p. 101; Ch. et Schl. in 
Linnea, ii. p. 208, t. 5. fig. 17 ; Kunth, Enum. Pl. iii. p. 132 ; A. Gr. Man. Bot. Northern 
U.S. ed. 5, p. 486 ; S. Wats. in Proc. Am. Acad. xviii. p. 169. 
Canapa to Trexas.—Norta Mexico, region of San Luis Potosi 6000 to 8000 feet 
(Parry & Palmer, 856), near Morales (Schaffner, 549). Hb. Kew. ' 
3. Potamogeton liebmanni, Buchenau in Abhandl. Naturw. Verein, Bremen, 
iii. 1873, p. 349. 
Sour Mexico, Pital (Liebmann). 
4. Potamogeton lonchites, Tuckerman in Am. Journ. Sc. & Arts, vi. 1848, 
p- 226; Walp. Ann. iii. p. 505; A. Gr. Man. Bot. Northern U.S. ed. 5, p. 486; S. Wats. 
Bot. Calif. ii. p. 196. | 
New Enevanp to I[LLiNo1s and southward.—Soutn Mexico, near Tacubaya (Schaffner ; 
Bourgeau, 901), Jalapa (Galeotti). Hb. Kew. 
5. Potamogeton lucens, Linn. Sp. Pl. ed. 1, p. 126; Kunth, Enum. PI. iii. 
p. 132; A. Gr. Man. Bot. Northern U.S. ed. 5, p. 487; S. Wats. Bot. Calif. ii. p. 196 ; 
Griseb. Fl. Brit. W. Ind. p. 506. 
Norra AMERIcA.—GuaTEMALA, Atitlan, near San Lucas (Bernoulli, 598).—West 
-Invies; Evrorz; Norra Arrica; Norra Asta; Norra-west Inpia. Hb. Kew. 
6. Potamogeton natans, Linn. Sp. Pl. ed. 1, p. 126; Kunth, Enum. PI. iii. 
p. 127; S. Wats. Bot. Calif. ii. p. 195, et in Proc. Am. Acad. xviii. p. 169; A. Gr. 
Man. Bot. Northern U.S. ed. 5, p. 484. _ 
North Amertca—Norra Mexico, San Luis Potosi (Schaffner, 535), Zacatecas 
(Hartweg, 243); Sours Mexico, Guanajuato (Dugés)—One of the common species, 
having nearly the same range as the genus. Hb. Kew. | 
7. Potamogeton pauciflorus, Pursh, Fl. Am. Sept. i. p. 121; Ch. et Schl. in 
Linnea, ii. p. 176, t. 4. fig. 7; Kunth, Enum. Pl. iii. p. 136; A. Gr. Man. Bot. Northern 
U. S. ed. 5, p. 489; S. Wats. Bot. Calif. ii. p. 197, et in Proc. Am. Acad. xviii. p. 169. 
BIOL. CENTR.-AMER., Bot. Vol. III., February 1885. 31 
