CRUCIFEROUS TRIBE 



25 



damper places continues in flower ali the 

 summer. The leaves and young flower- 

 stems afford an agreeable salad. The 

 flowers are white, very small, and often 

 imperfect, and are soon overtopped by the 

 lengthening pods, the valves of which, 

 when ripe, curl up with an elastic spring 

 if touched, and fly off, scattering the seeds 

 to a considerable distance. Fl. all the 

 summer. Annual. 



5. C. bulla f era (Bulbiferous Bitter Cress, 

 Coral-root). Stem erect, about 18 inches 

 high, unbranched. Well distinguished from 

 any other British plant in the order, by its 

 purple flowers, its whitish toothed roots, 

 and dark purple, scaly bulbs, which grow 

 in the axils of the upper leaves, and falling 

 off when mature produce new plants. 

 Seeds are seldom produced, the plant 

 depending for propagation upon the axil- 

 lary bulbils. 



Cardamine Bulrifera 



(Bulbiferous Bitter Cress. 



Coral-Root) 



*fj 



Aratis Pfrfoi.iata 



iGlnh*n US i^ck Cress ; Tower 



Mustard) 



15. Arabis (Rock Cress) 



1. A. perfoliata (Glabrous Rock Cress, 

 Tower Mustard). Stem erect, about 

 2 feet high ; stem-leaves glabrous ; 

 clasping the stem ; root-leaves slightly 

 hairy; flowers pale yellow, small. It 

 grows on banks and open places, widely 

 distributed in England, but never very 

 common. 



2. A. turrita (Tower Cress). Stem 

 about 1 foot high ; plant rough with 

 forked hairs ; stem-leaves clasping the 

 stem ; flowers whitish yellow ; pods 

 curved downwards as they ripen. 

 Naturalized on old walls at Oxford and 

 Cambridge, but not a true native of 

 Britain. Fl. May to July. Biennial. 



3. A. hirsuta (Hairy Rock Cress). A 

 stiff, erect plant, about a foot high. 

 Leaves rough with hairs, those of the 

 stem numerous, clasping the stem ; 

 flowers small, white. Frequent in many 

 parts of Great Britain on walls anrl 

 bank<=. Fl. June, July. Biennial. 



