CRUCIFEROUS TRIBE 



damper places continues in flower al] 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 elai;tic spring 

 if touched, and fly off, scattering the seeds 

 to a considerable distance. — Fl. all the„ 

 summer. Annual. 



5. C. hiilbifera (Bulbiferous Bitter Cress, 

 Coral-root). — Stem erect, about 18 inches 

 high, unbranched. Well distinguished from 

 any other British plant in the order, by it.s 

 purple flowers, its whitish toothed roots, 

 and dark purple, scaly bulbs, which grow 

 in the axils of the upper leaves, and fallmg 

 off when mature produce new plants. 

 Seeds are seldom produced, the plant 

 depending for propagation upon the axil- 

 lary bulbils. 



25 



Cardamine Bulbifer.i 



{Bulbiferous Bitter Cress, 



Coral-Root) 



Ar 

 {Glabr 



15. Arabis {Ro€k Cress) 



1. A. perfoliata (Glabrous Rock Cress, 

 Tower Mustard). — Stem erect, about 

 2 feet high j stem-leaves glabrous ; 

 clasping the stem ; root-leaves .slightly 

 hairy ; floivers 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 I foot high ; plant rough with 

 forked hairs ; stem-leaves clasping the 

 stem ; flmvers whitish yellow ; fods 

 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. hirsiita (Hairy Rock Cress). — A 

 .^ stiff, erect plant, about a foot high. 



^j-' wv 7^\ 'f^^^^ Leaves rough with hairs, those of the 



'^fh'^^ stem numerous, clasping the stem; 



ARTS Perfoliata flowers small, white. Frequent in many 



parts of Great Britain on walls and 



banks. — Fl. June, July. Biennial, 



us Rock Cress 

 Mustard) 



Tower 



