CRUCIFERiE. 51 



Root anmial. Stems slender, branched, erect, leafy, 4-12 in. 

 high. Root-leaves obovate, tapering below, in a lax rosette, entire 

 or toothed at the summit ; stem-leaves ovate, acute, toothed all 

 round, clasping with two rounded ears (auricles or lobes) . Petals 

 longer than the sepals, rounded at the apex, abruptly contracted 

 into the claw. Style nearly obsolete. Pouches elliptical or ob- 

 long, riiore or less spreading, and inclined towards the general 

 peduncle (stalk) in long lax clusters. — A slenderer and less erect 

 plant than D. incana. 



On limestone rocks. Yorkshire and elsewhere, on elevated 

 calcareous places. Annual ; April-May. 



D. incana, L. Hoary Whitlow-grass. — e.b. 388. l.b.s. 77. 

 A. 9. C. 15. Lat. 53-61°. Alt. 0-1100 yds. Tern. 46-36°. 



Root long and tapering. Stem 12-18 in. high, but often less 

 and sometimes more, erect, simple, very leafy ; herbage hoary, 

 with crowded, appressed hairs. Root -leaves elliptic-lanceolate, in 

 a rosette ; stem-leaves ovate, sessile, clustered, elongate. Pedicels 

 not more than half the length of the pouch. Petals white, ob- 

 cordate, twice as long as the sepals. Pouch elliptic-oblong or 

 lanceolate, nearly half an inch long, slightly twisted, crowned with 

 the short thick style and depressed capitate stigma. 



On limestone rocks near Settle, and in North Wales. Peren- 

 nial; June-July. 



D. rupestris, Br. Simple-haired Whitlow-grass.— ^.b. 1338. 

 L.B.S. 7Q. 



A. 2. C. 3. Lat. 56-59°. Alt. 900-1300 yds. Tern. 36-34°. 



Root somewhat creeping, subdivided at the crown, and bearing 

 several tufts of oblong-linear, long-fringed leaves. Stem branched, 

 very short, each branch bearing a short, slender flower-stalk and 

 a shorter barren stalk ending in a tuft of leaves. Leaves nearly 

 radical, flat, lanceolate-elliptic, with forked hairs or bristles. 

 Flowers white, in small terminal clusters. Petals twice as long 

 as the sepals, with a notched limb. Fruit (pouch) much longer 

 than the pedicel, slightly twisted, hairy, with a short, stout, cylin- 

 drical rounded beak. 



Alpine places. Perennial ; July. 



D. aizoides, Lin. Yellow Whitlow-grass. — e.b. 1271. l.b.s. 

 75. 



A. 1. C. 1. Lat. 51-52°. Alt. ? Tern. 50°? 



Root perennial. Stems several, branched, each branch bearing 



