LIST OF HIGHER SEED-PRODUCING PLANTS. 137 



Disgrega Hassk. Comniel. Ind. 6 (1870), 

 Skofitzia Hassk. Oest. Bot. Zeitschr. 147 (1872). 

 Benth. and Hook., Qen. PI. Ill, 853; Durand, Ind. Gen. Phan. 435; 

 Engler and Prantl, Nat. Pflanz. 2, IV, 68 (Schonland); Schenck, Palaeo- 

 phyt. 367. 



Living species: 32; tropical and temperate America. 



N. America, 5; S. Sts., 4; E. Sts., 2; Rocky mts., 1. 



Fossil species: ? Commelinncites, amber (Conwentz). 



Tradescantia virginica Linn. Spec. 288 (1753). 



T. cristata Walt. F1. Car. 119 (1788). 

 T. ohioensis Kaf. N. F1. 86 (1836). 

 Wats, and Coult., Gray's Man. 6 ed. 539; Britt., Fl. N. J. 248; Webb., 

 Fl. Neb. 107; Chap., Fl. S. St. 498: Upham, Fl. Minn. 149; Coult., Fl. Colo. 

 355; Engl. Schiinland, 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; Holzinger294.W\nom>Go.; Oestlund 209, Minneapolis; 

 Sandherg 597, Cannon Falls; Herb. Sheld. 1711, Minneapolis; 

 Hammond 50, Lake City; Wickersheim 130, Idlewild. 



XV. PONTEDERIACEAE. Pickerel-Weed 

 Family. 



Endlicher, Gen. PI. 137 (1840); Benth. and Hook., Gen. PI. Ill, 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 (1737). 



Unisema Raf. Journ. Phys. LXXXIX, 261 (1819). 

 Reussia Endl. Gen. 139 (1840). 

 Engler and Prantl, Nat. Pflanz. 2. IV, 73, 74 (Schonland); Durand^ 

 Ind. Gen. Plum. 433; Benth. and Hook., Gen. PI. Ill, 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. angnstifolia Pursh, Fl. Am. I, 233 (1814). 

 Wats, and Coult., Gray's Man. 6 ed. 536; Britt., Fl. N. J. 246; Mac.» 

 Fl. Can. II, 53: Upham, Fl. Minn. 149; Chap., Fl. S. St. 496; Engl. Schonl., 

 Nat. Pflanz. II, 4, 73; Gov., Fl. Ark. 226. 



