CRUCIFEEjE. 



45 



short and thick style, is often considered as a species, under the name 

 of B. prcecox (Eng. Bot. t. 1129), but it passes by every gradation into 

 those which have a pointed style of 2 lines, and which have again been 

 distinguished under the name of B. stricta. 



IV. WATERCRESS. NASTURTIUM. 



Glabrous perennials or annuals, with the leaves often pinnate, or 

 pinnately lobed, and small white or yellow flowers. Calyx rather loose. 

 Stigma capitate, nearly sessile. Pod linear or oblong, and usually 

 curved, or in some species short like a silicule, the valves very convex, 

 with the midrib scarcely visible. Seeds more or less distinctly arranged 

 in two rows in each cell, and not winged. Radicle accumbent on the 

 edge of the cotyledons. 



A small genus, but widely spread over the whole area of the family. It 

 differs from Sisymbrium, only in the position of the radicle in the embryo ; 

 and the white-flowered species are only to be distinguished from Bitter- 

 cress by the seeds forming two distinct rows in each cell of the pod. 



Pod usually half an inch long or more. 



Flowers white 1. Common W. 



Flowers yellow .2. Creeping W. 



Pod usually \ inch long or less. Flowers yellow. 



Pod oblong, curved. Petals scarcely longer than the calyx 3. Marsh W. 



Pod ovoid, straight. Petals longer than the calyx ... 4. Great W. 



1. Common Watercress. Nasturtium officinale, Br. (Fig. 

 {Sisymbrium Nasturtium, Eng. Bot. t. 855.) 



Stem much branched, sometimes very 

 short and creeping, or floating in shal- 

 low water ; sometimes scrambling on 

 banks or bushes to the length of 2 feet 

 or more. Leaves pinnate, with distinct 

 segments, the terminal one usually long- 

 er, ovate or orbicular. Flowers small and 

 white, in short racemes. Pods about 6 

 or 8 lines long or rather more, on spread- 

 ing pedicels, but slightly curved upwards, 

 the double rows of the seeds very distinct. 



Along brooks and rivulets, throughout 

 Europe and Russian Asia, except the ex- 

 treme north, and naturalized in North 

 America and some other countries. Abun- 

 dant in Britain except in some of the 

 Scotch Highlands. FL the whole sum- 

 mer. Fig. 51. 



51.) 



