CISTACEAE 447 



4. Triadenum Raf. 



1. T. virginicum (L.) Raf. In swamps: Lab. to Fla., Man., 



Neb. and La. 



Common throughout the range. 



The reported occurrence of T. petiolatum (Walt.) Britton, in N. J., rests on a specimen 

 collected " near Camden ' ' many years ago. It has never been seen since. 



ELATINACEAE 

 1. Elatine L.* 



1. E. americana (Pursh) Arn. Margins of pools and in slow 



streams: Me. and Ont. to Va., Mo. and Tex. Also in Colo. 

 and Oregon. 

 Scattered and local in most parts of the area. 



CISTACEAE 



Petals 5, yellow, fugacious or wanting. 



Leaves broad, lanceolate or oblong. I. Crocanthemum. 



Leaves subulate or scale-like, imbricated; style long. 2. Hudsonia. 



Petals 3, not yellow, persistent; flowers minute; style none. 3. Lechea. 



i. Crocanthemum Spach. [Helianthemum of Amer. Auth.]. 



Petaliferous flowers 5-12, in a short, terminal, cymose raceme, their 

 capsules 3—4 mm. long. 

 Petaliferous flowers short-pedicellcd, their pods thicker than 1. C. majus. 



long. 

 Petaliferous flowers long-pedicelled,their podslonger thanthick. 2. C. propinquum. 

 Petaliferous flowers solitary, rarely 2, their capsules 6-8 mm. long. 



Leaves oblong, acute; branches erect. 3. C. canadense. 



Leaves oval or elliptic; branches spreading. 4. C. dumosum. 



i. C. majus (L.) Britton {Helianthemum majus (L.) B. S. P.). 

 In dry soil: N. S. to S. Dak., Neb., N. Car. and Tex. 

 Conn. Not very common throughout the state, decreasing inland. 

 N. Y. Common on L. I. and S. I., decreasing up the Hudson 



Valley to Pine Plains, Dutchess Co., unknown northward. 

 N. J. Common throughout the state, except in the pine-barrens. 

 Pa. Montgomery, Bucks, Delaware and Chester counties. 



Tertiary, common: Cretaceous, less ccmmon: Older Formations, 

 scattered. Predominating south of the moraine. 143-220 days. 

 Sea level-900 ft. 



2. C. propinquum Bicknell. Dry soil: E. Mass. to N. J. 



N. Y. Not uncommon on L. I. 

 N. J. Landisville. 

 * See footnote, page 76. 



