24 CRUCIFERiE. 



solitary, and opposite the lateral sepals, and four longer, in 

 pairs, opposite the anterior, and posterior sepals. Disk with 

 various green glands between the petals and the stamens and 

 ovary. Ovary superior, 1 -celled. Stigmas 2. Fruit a silicule 

 or silique (pouch or pod,) rarely 1 -celled and valveless, gene- 

 rally 2 -celled and 2-valved, 1 or many-seeded, indehiscent or 

 opening by the two valves. Seeds attached in a single row by 

 a cord to each of the placentae, generally pendulous, without 

 albumen ; the embryo with the radical folded upon the cotyle- 

 dons. — Herbaceous plants. Leaves alternate. Flowers usually 

 yellow or white, in corymbs or racemes. 



I. SIIuICUIjOS M.— Pod short and broad (pouch.) 



1. CAKILE. Linn.— Sea. Rocket. 

 (An old Arabic word, applied probably to this or some allied genus.) 

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

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

 times abortive) pendulous. 



C. Americana Nutt. : leaves fleshy, obovate, attenuate at base, more or 

 less toothed and lobed ; joints of the pouch 1-seeded ; the uppermost one 

 ovate, acute* C. maritima, var. Americana Torr. Bnnias maritima 

 Pursh. B.mentula Big. 



Sea shores. Can. to Geor. Shores of the Great Lakes. July, Aug. (J). — 

 Plant fleshy, branched and decumbent. Flowers corymbed, pale purple. 



American Sea Rocket. 



2. THLASPI. Linn.— Penny Cress. 



(From the Greek 0Xou, to flatten ; probably on account of its compressed 

 seed vessels.) 



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



the back ; cells 2 — many-seeded. Petals equal. Calyx equal 



at base. 



1. T. arvense Linn.: leaves oblong-sagittate, coarsely toothed, smooth ; 

 pouch suborbicular, shorter than the pedice^ its wings dilated longitudinally. 



Stony fields. Can and N. S. W. to Miss. June. Q.—Stem a foot high, 

 erect, somewhat branched. Leaves smooth. Flowers small, white, in a ra- 

 ceme. Pouch very large, with dilated wings. Perhaps introduced. 



Penny Cress. 



2. T. tuberosum Nutt. : leaves rhombic-ovate, obsoletely toothed, smooth, 

 sessile ; radical ones upon long petioles ; stem pubescent, very short and 

 simple ; root tuberous ; pouch suborbicular, short. 



Penn. Nutt. April, May. (T). — Stem 4 — 5 inches high. Flowers large 

 rosaceous. Tuberous Penny Cress. 



