130 TETRADYNAMIA SILICULOSA. [CI. 15. 



** Bracteas three to each flower. 



5. O. ccerulea, 6. 423. (Purple B.) Stem simple. Bracteas three. 



Upper lip of the corolla cloven and notched ; lower in three 

 equal entire segments. St} r le downy. 

 Grassy past, near the sea. If. 7. Stem straight, dark grey. Fl. 

 bluish violet. 



6. O. ramosa, 3. 184. (Branched B.) Stem branched. Bracteas three. 



Upper lip of the corolla deeply cloven ; lower equally lobed ; 

 seg-ments all rounded and entire. Style smoothish. 

 Rich fields, on roots of hemp. 0. 8, 9. Spread. Fl. light purple. 



Class XV. TETKADYNAMIA. Stamens 

 6 ; the 2 opposite ones shortest. 



This ivhole Class constitutes an entirely Natural Order, 

 the Crucifer^e. 



[Cruciferous plants are generally herbaceous ; if shrubby, of 

 humble growth. Stein round. L. mostly alternate ; rarely compound. 

 Fl. in clusters, or corymbs; without bracteas; generally white or yellow; 

 often fragr., especially at night ; all complete and perf. Cor. of 4 pet. 

 cruciform. Qualities rather acrid, most wholesome when boiled ; 

 seeds warm and pungent.] 



Order I. SILICULOSA. Fruit a short roundish pod, 



or pouch. 



* Cotyledons accumbent. 



318. DRA.BA. Pouch entire, laterally compressed ; valves nearly 



flat. Seeds numerous. 



316. VeLLA. Pouch entire, with a prominent, dilated, flat style, 

 twice as long as the concave valves. 



330. CRA.MBE. Pouch globose, stalked, coriaceous, of 1 cell, with- 

 out valves, deciduous. Seed solitary. 



329. CAKlLE. Pouch angular, of 2 joints, each of 1 cell, without 

 valves ; the uppermost deciduous. Seed solitary. 



322. HUTCH INS I A. Pouch nearly entire ; valves keeled, not 

 bordered. Seeds 2, at least, in each cell. Filaments simple. 



319. ALf SSUM. Pouch nearly entire, bordered, laterally com- 



pressed ; valves concave. Seeds 1 or 2 in each cell. Filam. 



often toothed. 

 325. COCHLEARIA. Pouch nearly entire, turgid, rugged, of 2 



valves. Seeds numerous. 

 324. THLaSPI. Pouch cloven, inversely heart-shaped; valves 



with a bordered keel. Seeds numerous. 



