3S 



CRUCIFERiE 



media. — A variety with double flowers is frequent in gardens under 

 the name of Yellow Rocket. — Fl. May — August. Biennial. 



2.^ B. verna (American Cress), differing in a more slender 

 habit, narrower leaves^ \si\gerfI02vers in a closer raceme and longer 

 pods^ and flowering earlier, is a common garden escape, being 

 grown as a salad. 



5. Arabis (Rock Cress). — Herbs growing in dry places, mostly 

 local in Britain ; radical leaves spathulate; flowers small ; sepals 



short ; petals clawed ; pods 

 linear, compressed, keeled, 

 not elastic. (Name from 

 Arabia, the native country 

 of several of the species.) 



1. A. alpina (Alpine 

 Rock Cress). — A low-grow- 

 ing plant, with its cauline 

 leaves downy with branched 

 hairs, lanceolate, acute, 

 amplexicaul, toothed, and 

 its pods erect, on spread- 

 ing hairy stalks, occurs on 

 the Cuchullin Mountains 

 in the Isle of Skye. Peren- 

 nial. 



2. A. petrcea (Mountain 

 Rock Cress). — Generally 

 glabrous ; stem 3 — 8 in. 

 high, branched below ; 

 radical leaves lyrately pin- 

 natifid ; cauline leaves sub- 

 entire, stalked ; flowers 



corymbose, white, tinged with purple. — On rocks in Wales and 

 Scotland. — Fl. June — August. Perennial. 



3. A. scdbra (Bristol Rock Cress), with hispid, sinuate-dentate 

 radical leaves., sessile cauline leaves and cream-coloured flowers., 

 grows on limestone rocks at Bristol and Cheddar. — Fl. March — 

 May. Perennial. 



4. A. cilidta (Ciliate Rock Cress), with leaves smooth on both 

 sides, but fringed with forked hairs at the edges, and white 



flowers^ grows on rocks by the sea near Tenby, and in the south 

 and west of Ireland. — Fl. July, August. Perennial. 



5. A. hirsiita (Hairy Rock Cress). — Hispid ; stems many, about 

 I foot high, with numerous cauline leaves, heart-shaped at the base 



BARBAR^A -VULGARIS {CoDimon IVintcr C7-ess). 



