888 DRABA. [CLASS XV. order r. 



the crevices and inequalities of the stone, and is enabled to bear all the 

 vicissitudes of its exposed situation. From its hardy habit and showy 

 flowers, it is well adapted for rock work, and the more exposed it is 

 the more it seems to flourish and flower luxuriantly ; it is one of those 

 early harbingers of Spring, which remind us of the vernal response — 

 " I come ! I come ! — ye have called me long ; 



] come o'er the mountain with light and song ! 



Ye may trace my steps o'er the wakening earth, 



By the winds that tell of the violet's birth, 



By the primrose stars in the shadowy grass^ 



By the green leaves opening as I pass." Hemans. 



3. D. rupes*tris, Br. (Fig. 1025.) Rock Whitlotv Grass. Scape 

 round, and as well as the pedicles hairy, often bearing one or two 

 leaves at the base ; petals while, longer than the calyx, slightly 

 notched ; silicula oblong, ovale, hairy, with a very short style ; leaves 

 flat, lanceolate, hairy. 



Hooker, British Flora, ed. 4. vol. i. p. 250. — Lindley, Synopsis, p 

 26.— D. hirta.—EngVish Botany, t. 1338.— English Flora, vol. iii. 

 p. 159. 



Root of very long slender branched fibres. Stems several, round, 

 slender, hairy, repeatedly branched, and bearing a tuft of numerous 

 crowded lanceolate leaves, tapering at the base, flat, more or less thickly 

 scattered over with simple rigid hairs, sometimes there are a few 

 forked ones mixed amongst them. Scapes mostly several from the 

 same root, from one to two inches high, round, slender, clothed with 

 spreading hairs, and often bearing near the base one or two leaves, and 

 bearing at the top a few white Jlowers, in a sub-corymbose form, each 

 on a slender hairy pedicle, and sometimes one or two of the lower ones 

 arising from the axis of a small leaf. Calyx oblong, mostly hairy, the 

 margins white, membranous. Corolla of four oblong wedge-shaped 

 white petals, obtuse, often slightly notched, and about as long again as 

 the calyx. Stamens with simple filaments and yellow two celled 

 anthers. Fruit an ovate oblong compressed silicula, scattered over 

 with forked or starry pubescence, rarely smooth, and crowned with a 

 very short thick style and obtuse stigma, two celled, each cell containing 

 several small pale brown ovate flat seeds. 



Habitat. — Mountains, rare; upon the summit of Ben Lawers and 

 Cairngorum, and Ben Hope, Scotland. 



Perennial ; flowering in July. 



4. D. inca^na, Linn. (Fig. 1026.) Twisted podded Whitloiv Grass. 

 Stem with deeply toolhed lobes, and hoary, with starry pubescence, the 

 radical ones lanceolate, numerous; petals much longer than the calyx ; 

 silicula elliptic, oblong, smooth, somewhat twisted, longer than the 

 hairy pedicles. 



English Botany, t. 388. (large from a cult, specimen). — English 

 Flora, vol. iii. p. 161. — Hooker, British Flora, ed. 4. vol. i. p. 250. — 

 Lindley, Synopsis, p. 26.— Z>. contorta, De Cand. Prod. 1, p. 170. 



