i6 THE FLORA OF THE ALPS 



Order VL— CRUCIFERiE. 



Flowers regular, mostly white or yellow, in bractless 

 racemes; sepals 4; petals 4; stamens 6, of which 2 have 

 shorter filaments than the other 4 (rarely only 4) ; fruit 

 a siliqua or silicule. A very large order of herbaceous 

 plants, most abundant in the Temperate and Arctic regions 

 of Europe and Asia. 



Tribe Arabide^. — Seed-vessel elongated, much longer 

 than broad (a siliqua) ; seeds in one or two rows ; radicle 

 accumbent. Genera 1-7. 



I. Matthiola, Br. 



Stigma erect or decurrent on the style; flowers 

 large, lilac. 



M. valesiaca, Boiss., a woolly plant with flowers a 

 dirty violet, is recorded from Southern Switzerland and 

 Tirol 



2. Cheiranthus, L. 



Stigma terminal ; flowers large, yellow or variegated ; 

 lateral sepals saccate at the base. Not alpine. 



C. Cheiri, L., Wall-flower; on walls and rocks in 

 Southern Switzerland, often introduced. 



3. Nasturtium, Br. 



Stigma terminal ; flowers yellow or white ; sepals 

 equal at the base; seed-vessel turgid; seeds in two 

 rows. 



N. pyrenaicum^ R.Br., the only sub- alpine species, 



