CRUCIFER^E. 25 



Div. I. SILICULO&E. 



1. CAKILE. Linn. 



Pouch 2-jointed, compressed ; the upper joint ensiform or 

 ovate. Seed solitary in the cells ; upper erect, lower pendu- 

 lous. Tetradynamia. Siliculosa. 



C. americana Nutl. : leaves fleshy, oblong, obtuse, with the margins 

 toothed ; joints of the pouch 1-seeded ; the uppermost one ovate, 

 acute. C. maritima, var. americana, Torr. Bunias maritima Pursh 

 B. cdentula Big. 



HAB. Sea coast. N. S. Shores of the great Northern lakes, 

 Nutt. July Oct. 0. Plant fleshy, branched and decum- 

 bent. Flowers purple, corymbed. American Sea Rochet. 



2. THLASPL Linn. 



Pouch emarginate at the apex ; valves boat-form, winged 

 on the hack ; cells 2 many seeded. Petals equal. Calyx 

 equal at base. Tetradynamia. Siliculosa. 



1. T. arvcnse Linn. : leaves oblong-sagittate, coarsely toothed, 

 smooth ; pouch suborbicular, shorter than the pedicel ; its wings dilat- 

 ed longitudinally. 



HAB. Stony fields. Can. and N. S. W. to Miss. June. 0. 

 Stem a foot high, erect, somewhat branched. Leases smooth. 

 -;. Flowers small, white, in a raceme. Pouch very large, with dilat- 

 ed wings. Penny-cress. 



2. T. tubcrosum Nutt. : leaves rhombic-ovate, pbsoletely toothed, 

 smooth, sessile ; radical ones upon long petioles ; stem pubescent, 

 very short and simple ; root tuberous ; pouch orbicular. 



HAB. Penn. Nutt. April, May. @. Sttm 4 5 inches high. 

 Flowers large, rosaceous. 



3. CAPSELLA. De Cand. 



Pouch triangular, wedgeform at base ; valves boat-form, 

 not winged ; cells many-seeded. Tetradynamia. Siliculosa. 



C. pursa-pastoris De Cand. ; radical leaves pinnatifid. 



HAB. Cultivated grounds. Throughout the U. S. April Oct. 



0. Stem 6 12 inches high. Radical leaves pinnatifid, hairy : 



cauline ones oblong, toothed, sagittate at base. Flowers white, 



in terminal spiked racemes. Shepherd's Purse. 



4. ALYSSUM. De Cand. 



Pouch orbicular or elliptic ; valves flat, or convex in the 

 centre. Seeds 2 4 in each cell, compressed, sometimes sur- 



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