ffutchinsia.] VI. CRUCIFER^. 45 



XX. HUTCHINSIA. HUTCHINSIA. 



Dwarf annuals or perennials, with pinnate leaves and white flowers, 

 separated from Lepidium by having 2 seeds in each cell of the pod. 



A genus limited by some to one species, by others extended to a few 

 allied ones from southern Europe and Russian Asia, or also to some 

 perennials from the high mountains of central and southern Europe. 



1. H. petrsea, Br. (fig. 101). Rock E. — A glabrous, delicate, erect 

 annual, seldom 3 inches high, branching at the base. Radical leaves 

 about half an inch long, and pinnate ; stem-leaves few and smaller, with 

 fewer and narrower segments. Flowers very minute. Pod oval, rather 

 more than a line long. Radicle of the seeds incumbent on the back of 

 one of the cotyledons, but very near its edge. 



On limestone rocks, old walls, and stony places, in central and 

 southern Europe, from Sweden to the Crimea. Confined, in Britain, to 

 the limestone tracts of the west of England, Dumfries, and Wales, the 

 walls of Eltham churchyard and of a cemetery at Cork in Ireland. Fl. 

 spring. 



XXI. CAPSELLA. CAPSELL. 



Annuals, with entire or pinnate leaves and small white or purplish 

 flowers, distinguished from Lepidium and Butchinsia by having several 

 seeds in each cell of the pod, from Thlaspi by the pod not winged, and 

 the radicle incumbent on the back of one of the cotyledons. 



A genus of a single one, or of two or three, European and Asiatic 

 species, according to the limits assigned to it by different botanists. 



1 . O. Bursa-pastoris, Moench. (fig. 102). Shepherd' s-purse. — Root 

 tapering, often to a great depth. Radical leaves spread on the ground, 

 pinnatifid, with a larger ovate or triangular terminal lobe, or sometimes 

 entire. Stem erect, from a few inches to above a foot high, rather 

 rough and often hairy, with a few oblong or lanceolate, entire or 

 toothed leaves, clasping the stem with projecting auricles. Pods in a 

 long loose raceme, usually triangular, truncate at the top, with the 

 angles slightly rounded, and base narrowed, sometimes notched at the 

 top and almost obcordate. Seeds 10 to 12 in each cell. 



Probably of European or west Asiatic origin, but now one of the com- 

 monest weeds in cultivated and waste places, nearly all over the globe 

 without the tropics. Abundant in Britain. FL nearly all the year round. 



XXII. LEPIDIUM. CRESS. 



Annuals or perennials, glabrous or hairy, with numerous small white 

 flowers. Petals equal. Stamens without appendages. Pods ovate or 

 shortly oblong, rarely orbicular, compressed laterally (at right angles to 

 the narrow partition) ; the valves boat-shaped, either without wings or 

 the keel expanded into a narrow wing at the top. Seeds one in each 

 cell, the radicle usually incumbent on the back of the cotyledons. 



A numerous and rather natural widely diffused genus. It is readily 

 distinguished from Iberis by the small petals all equal, and from all 

 other British siliculose Crucifers, with laterally compressed pods, 

 except Senebiera, by the single seeds in each cell. 



