LIST OF HIGHER SEED-PROVDUCING PLANTS. 137 
Disgrega Hassk. Commel. Ind. 6 (1870), 
Skofitzia Hassk. Oest. Bot. Zeitschr. 147 (1872). 
Benth. and Hook., Gen. Pl. III, 853; Durand, Ind. Gen. Phan. 435; 
Engler and Prantl, Nat. Pflanz. 2, 1V, 68 (Schénland); Schenck, Palaco- 
phyt. 367. 
Living species: 82; tropical and temperate America. 
N. America, 5; S. Sts., 4; E. Sts., 2; Rocky mts., 1. 
Fossil species: ?Commelinacites, amber (Conwentz). 
Tradescantia virginica Linn. Spec. 288 (1753). 
T. cristata WALT. FI]. Car. 119 (1788). 
T. ohioensis Rar. N. FI. 86 (1836). 
Wats. and Coult., Gray’s Man. 6 ed. 539; Britt., Fl. N. J. 248; Webb., 
Fl. Neb. 107; Chap., Fl. 8. St. 498; Upham, FJ. Minn. 149; Coult., Fl. Colo. 
355; Engl. Schénland, Nat. Pflanz. II, 4, 68; Wats., King Exp. 359; Roth., 
Wheel. Exp. 274; Cov., Fl. Ark. 226. 
Mexico to Central America? 
North America: N. Y. to Minn., Dak. and Wyoming; 
S. to Fla. and N. Mex. 
Minn. valley: Throughout; meadows and edges of 
woods. 
HERB: Sheldon 747, Sleepy Eye; Taylor 176, Janes- 
ville; Taglor 578, Minnesota lake; Taylor 783, Glenwood; Bal- 
lard 368, Helena, Scott Co.; Ballard 58, Chaska; Herrick 319, 
Minneapolis; Herrick 320, Minneapolis; Kassube 250, Minne- 
apolis; Holzinger 294, Winona Co.; Oestlund 209, Minneapolis; 
Sandberg 597, Cannon Falls; Herb. Sheld. 1711, Minneapolis; 
Hammond 50, Lake City; Wickersheim 130, Idlewild. 
XV. PONTEDERIACEAE. Pickerel-~-Weed 
Family. 
Endlicher, Gen. Pl. 137 (1840); Benth. and Hook., Gen. Pl. III, 836 
(1883); Schonland in Engler and Prantl, Nat. Pflanz. 2, IV, 70 (1887). 
Genera: 6; warmer regions, except Europe. 
Species: 23; principally tropical. 
PONTEDERIA Linn. Gen. 291 (1787). 
Unisema Rar. Journ. Phys. UNXNIN, 261 (1819). 
Reussia ENDL. Gen. 139 (1840). 
Engler and Prantl, Nat. Pylanz. 2. IV, 738, 74 (Schonland); Durand, 
Ind. Gen. Phan. 433; Benth. and Hook., Gen. Pl. III, 837. + 
Living species: 3-4; N. America, 1; S. America, 3. 
Pontederia cordata LINN. Spec. 288 (1753). 
P. mucronata RAF. Med. Rep. XI, 352 (1808). 
P. angustifolia Pursu, Fl. Am. I, 233 (1814). 
Wats. and Coult., Gray’s Man. 6ed. 536; Britt. Fl. N. J, 246; Mac.» 
Fl. Can. II, 53; Upham, Fl. Minn. 149; Chap., Fl. 8. St. 496; Engl. Schonl., 
Nat. Pflanz. II, 4, 78; Cov., Fl. Ark, 226, 
