TAXONOMY NVMPHAEA TUBEROSA. 



191 



Stipules fused, whitish, appressed, broadly triangular, slightly emarginate, with a 

 swelling near the base, 1.4 cm. long by 1.4 cm. wide. 



Rhizome horizontal, stout, 2.5 to 5 cm. in diameter, 10 cm. to 90 cm. long; color 

 pale, almost obscured by fine dark hairs ; apex protected by stipules and long fine hairs. 

 Phyllotaxy 2 on 5, becoming less evident on older parts ; leaves 2 to 2.5 cm. apart. 

 Roots 8 or more from one leaf- 

 base. Branches numerous, 2.5 

 to 7 or 10 cm. apart ; originating 

 with strong connection (1.12 cm. 

 in diameter) with parent rhi- 

 zome, but the attachment later 

 becomes very slender (0.3 to 0.8 

 cm.) so that the pieces easily 

 break off, forming the so-called 

 tubers. Mature tubers 2.2 to 6 

 or 8 cm. long by 1.3 to 1.9 cm. 

 thick, occurring singly or in 

 groups of 2 to 5 from an origin- 

 ally single shoot. They are 

 loaded with starch, and show the 

 usual rhizome structure ; they 

 spring from any point without 

 any visible order on the parent 

 stem ; the connecting isthmus 

 shows (in transverse section) 3 

 vascular bundles with central 

 xylem, embedded in a mass of 

 large-celled, loose, starch-laden 

 parenchyma. 



GEOGRAPHIC DISTRIBUTION. 

 North and west of the Appa- 

 lachian Mountains in North 

 America : Lake Champlain, west 

 through the Great Lakes to 

 Minnesota, south to Arkansas. 



Very rare on the Atlantic Slope. FIG. "H.-Nymphaea tuberosa. Under side of leaf on right, 



Lake Hopatcono- New Tersev upper side on left; s.astomatic area; a, petiole, showing stripes; 



. - ' 6, stipule. Natural size of leaf 24.5 cm. long ; stipule reduced 



fid. Specimens cultivated at proportionately. Petiole enlarged. 



Riverton. Poeatquissing Creek, 



Mercer County, N. J. (Abbott 1888, and our own collections). Meadville, Pa. (Britton 

 & Brown 1897). Raquette River, New York (Prentiss in Bull. Torr. Bot. Cl., w: 43- 

 45). Ontario, Canada (Britton 1889 b). Grosse Isle, mouth of Detroit River (Campbell, 

 Bull. Torr. Bot. Cl., 13: 93-94, 1886). Southeastern Minnesota (Wheeler 1900). Ames, 

 Iowa (Hitchcock 1890). Swamps near Little Rock, Ark. (Branner & Coville 1888). 

 NOTES. A smaller variety from Lake Hopatcong, N. J., is known in gardens 



