CLASSES, &c. AND GENERA ARRANGED. cxix 



Class XV. TETRADYNAMIA. Six Stamens, four 

 longer than the rest. 



This class forms the Natural Order of Jussieu's Cruciferee, (Cru- 

 ciform plants,) in which the stem is round. Ls. generally alter- 

 nate. Fl. without bracteas, mostly white, or yellow. Cor. four- 

 petalled, cross-shaped, (cruciform.) Seeds warm, pungent. 



Order I. SILICULO'SA. Fruit a short pod, or pouch. 



The sections of this class, Teti'adynamia, are made from distinc- 

 tions in the cotyledons ; distinctions easily perceived by a removal 

 of the seed-skin. The two cotyledons are either incumbent, that is, 

 lying upon the embryo laterally, (sideways,) or accumhent, that is, 

 Avhen their edges, at one side, meet the embryo lengthwise.— 

 See notes, over leaf. 



* Cotyledons accumbent. 

 Draba. Wliitlow-grass . Pouch entire, (oval,) compressed side- 

 ways, (laterally.) Valves nearly flat. Seeds many. — Page 183. 

 HuTCHiNSiA. Pouch nearly entire ; valves keeled, not bordered. 

 Seeds two, at least, in each cell. Stam. -filaments simple. — Page 

 307. 

 CocHLEA'RiA, Scurvy-grass, (Horse-radish.) Pouch nearly entii'e, 



rugged ; valves two, swollen. Seeds many. — Page 185. 

 Thlaspi, Shepherd's Purse. Pouch cloven, inversely heart- 

 shaped; valves with a bordered keel. Seeds many. — Page 184. 

 IbE'RIS, Candy-tuft. Pouch cloven, inversely heart-shaped. Cells 



one-seeded. Pet. unequal.— Page 186. 

 Teesda'lia, Teesddlia, Stam. Filaments each bearing a scale 

 within at the base. Pouch cloven, inversely heart-shaped, 

 valves keeled. Cells two-seeded. — Page 184. 

 * * Cotyledons incumbent, 

 Cameli'na, Gold of Pleasure. Stam. -filaments simple. Pouch 

 entire; valves swollen. Seeds many, without border. — Page 

 183. 

 Senebi'era, Wart-cress. Pouch two-lobed, nearly entire ; trans- 

 versely compressed, wrinkled ; valves none. Seeds one in each 

 cell.— Page 186. 

 Lepidium, Pepperwort. Poxich cloven, elliptical, two-celled, the 

 two valves keeled. Cells one-seeded. — Pa^e 183. 



