CLASS XV. ORDER u.] CAUDAMTNE. 925 



footstalks, four or live pairs, and a terminal one, tlie lower ones 

 roundish, ovate, angularly tootlied, the upper linear, oblong, toothed, 

 or entire. Inflorescence terminal and lateral sub-corymbose clusters, 

 becoming much elongated racemes after flowering. Calyx of four 

 oblong jiuvplish pieces, with narrow membranous margins. Petals 

 four, white, about as long again as the calyx, oblong, tapering into 

 a short claw. Stamens four or six, erect, with awl- shaped yi/amen<« and 

 yellow anthers, of two cells. Sti/le short, thick. Stif/ma small, obtuse. 

 Fruit a linear compressed erect smooth siliqua, the seeds numerous, 

 compressed in a single row. 



Habitat. — Moist shady waste and cultivated places. 



Annual; flowering from March to June. 



5. C. impa'tietis, Linn. (Fig. 1070) Narrow-leaved Bitter-cress. 

 Leaves pinnate, auriculated at the base; leaflets of the lower leaves 

 petiolated, ovate, three or five-cleft, the upper oblong, lanceolate, 

 sessile, toothed, or entire; petals oblong, narrow, scarcely as long 

 again as the calyx; style short ; sligma obtuse. 



English Botany, t. 80. — English Flora, vol. iii. p. 187. — Hooker, 

 British Flora, ed. 4. vol. i. p. 251. — Lindley, Synopsis, p. 25. 



Root slender, tapering. Stem erect, about two feet high, angular, 

 furrowed, smooth, mostly zigzag, leafy and simple, or branched. 

 Leaves pinnate, the common stalk auriculated at the base, with awl- 

 shaped ciliated stipules, leaflets numerous, those of the lower leaves 

 on short footstalks, ovate, cut, or deeply toothed with two or three 

 lateral teeth, the upper leaves with oblong or lanceolate, mostly sessile 

 leaflets, entire, or slightly toothed. Inflorescence terminal sub- 

 corymbose racemes, becoming much elongated and lax after flowering. 

 Calyx nearly erect, of four ovate pale pieces. Petals oblong, or 

 obovate, small, a little longer than the calyx, white. Stamens with 

 slender filaments and small yellow anthers, of two cells. Fruit an 

 erect slender smooth narrow siliqua, terminating in a short tapering 

 style and small obtuse stigma Seeds numerous, compressed in a 

 single row. 



Habitat. — Moist rocks, rare ; in several parts of Derbyshire, 

 Leicestershire, Westmoreland, and Cumberland; near the falls of the 

 Clyde, and banks of the river Donne, Scotland. 



Annual ; flowering in May and June. 



This species is readily distinguished by its fringed stipules at the 

 base of the leaf stalks. The specific name of im;?a<ien« is applied to 

 this plant on account of the valves of the pods when ripe, suddenly 

 curling up on the least motion of (he plant, and throwing the 

 seeds to some distance; the cause of which action will be seen, 

 on examination of the pods, to depend upon their structure. The 

 valves are thin, elastic, ribless membranes, of condensed cellular 

 Substance ; the septum of the cells is a very delicate transparent 



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