78 NYIMPILEACE/E. ynphar. 



matic rajs 12 to 22, usually not attaining the edge of the disk; fruit ovate, with thick more 

 or less costate scarcely constricted neck. — Kew. ed. 2, iii. 295; Pursh, Fl. ii. 369; Gray, 

 Geu. lU. i. 104, t. 44; Meehau's Monthly, i. 17, 18, t. 2. N. lutca, Pursh, 1. c. ; DC. Syst! 

 ii. 60, as to Anier. plant; ' Hook. Fl. Bor.-Am. i. 32; Torr. & Gray, Fl. i. 57, excl. var. 

 and (?) Alaskan plant. N. Amaicanum, Provancher, Fl. Canad. i. 28. Xt/mphcra lutea, 

 Walt. Car. 154. iV. advena, Ait. Kew. ii. 226; Willd. Ilort. Berol. t. 38; Sims, Bot. Mag. 

 t. 684. iV. arifolia, Salisb. Ann. Bot. ii. 71. — Labrador to Florida, Texas, Wyoming, 

 and doubtfully to California; common throughout the Eastern and Middle States, mucli 

 rarer if present upon the Pacific Slope. (Cuba.) Var. vakiecAtcm, Engelm. (in Gray, 

 Man. ed. 5, 57) is a frequent form with sepals a brighter yellow toward the edges, and 

 some at least red-purple or maroon toward the ba.se witliin ; the sinus of the leaf commonly 

 narrow or dosed. — Growing with the duller flowered type, but in some jdaces the com- 

 moner or only form. 



Var. minus, Mokong. Similar in general aspect: leaves and flowers smaller ; jjctiolcs 

 and peduncles more flaccid; a few thin submersed leaves commonly present: stigmatic disk 

 smaller, bright red (occasionally green or yellow), 9-12-rayed, rather deeply crenate, only 

 3 to 4 lines in diameter; ovary and fruit somewhat smaller and v/ith a strongly constricted 

 neck. — The var. (?) minor, Morong (Bot. Gaz. xi. 167), as taken by Wats. & Coulter in 

 Gray, Man. ed. 6, 56, to include N. ruhrodiscum, Morong, 1. c, which cannot be satisfac- 

 torily distinguished from Dr. Morong's type of his var. minor. N. luteum, Gray, Man. 24, 

 excl. var, and not of Smith. N. adcena X Kalmiana, Casp. in Macoun, Cat. Canad. PI. 32. 

 N. F/etclteri, Lawson, 1. c. 119. Ni/mpha^a ruhrodisca, Greene, Bull. Torr. Club, xv. 84. — 

 An exact intermediate between N. advena and the following species, and, with little doubt, 

 of hybrid origin, frequently associated with the parent plants in Lower Canada, Ontario, 

 and the Northern States, westward at least to Minnesota, gro\\'ing in sliallower water than 

 N. advena, and often showing imperfect pollen as though only partially fertile ; in other 

 localities, however, as in Lake Champlain, appearing (ace. to Dx. Morong) thoroughly inde- 

 pendent and fertile ; so that it may be best regarded as a perpetuated or established hybrid, 

 lutergradation (probably rehybridization) ^vith the parent stocks, especially toward N. ad- 

 veun, makes specific distinction undesirable. Fretpient and very similar hybrids between 

 N. minimum and A^. luteum have been repeatedly noticed in Europe by ('aspary and others. 

 -(- •)— Anther-cells (at maturity) only a third as long as the filaments: .stigmatic disk 



small, 2 to 3 lines in diameter, about 8-rayed 



N. minimum, Smith. TJootstock horizontal, slender, enveloped at the end by the sheath- 

 ing membranous expanded bases of the slender flaccid petioles: floating leaves 1^-3 (-4) 

 inches long, usually pubescent beneath ; the sinus reaching almost to the middle of the leaf; 

 submersed leaves freely produced, suborbicular, very delicate, membranaceous and tran.s- 

 iuc«nt ; sinus more open : sepals about 5, suborbicular, 6 to 8 lines in diameter, yellow . 

 petals obovate-cuneate, 2 lines long, half as broad : stigmatic disk distinctly lobed, deep red 

 or (at least in the European form) green ; stigmatic rays yellow; fruit ovoid, 6 to 8 lines in 

 diameter, -with short slender neck. — P^ng. Bot. xxxii., description of t. 2292; Hook. f. & 

 •Tacks. Ind. Kew. ii. 320. N. pumilum, DC. Syst. ii. 61 ; Smith, 1. c. on plate; Casp. in Miq. 

 Ann. Mus. Lugd.-Bat. ii. 256; Wats. Bibl. Index, 37. N. Kalmiatia, Ait. f. Kew. ed. 2, iii. 

 295 ; Pursh, Fl. ii. 369. N. lutea, var. Kalmiana, Torr. & Gray, Fl. i. 58. N. luteum, var. 

 pumilum, Gray, Man. ed.-5, 57. Nj/mpkcen microphi/lla, Pers. Syn. ii. 63. N. Knlmiaha, Sims, 

 Bot. Mag t. 1243. — Ponds from Newfoundland to the Saskatchewan, southward to Pennsyl- 

 vania. (Eu.) 

 * * Leaves elongated-oblong, sagittate; the blade 6 to 10 times as long as the sinus: 



flowers small, an inch to inch ai\d a third in diameter when open : southern Atlantic 



species. 



N. sagittaefolium, PmsH. Phizome apparently horizontnl, or oblique, sending off stout 

 roots : petioles long and rather slender : leaves thin and relatively much narrower than in 

 any of the other American s])ecies; the floating ones narrowly elliptic-oblong, 7 to 12 inches 

 in length, Ii to 2i inches broad; the submersed considerably larger, delicately membrana- 

 ceous: sepals about 6 or 7 ; the outer green ; the inner petaloid at least near the edges: petals 

 spatulate, truncate, thickish (said sometimes to be completely transformed into stamens) : 

 stamens in 4 to 6 rows ; anthers fully as long as the flat filaments : dit^k 4 to 6 lines in 



