DIPLOTAXIS.] CRUCIFER^E. 31 



10. DIPLOTAXIS, DC. ROCKET. 



Annual or perennial herbs. Leaves pinnatifid. Flowers yellow. Sepals 

 spreading, equal. Pod narrow, elongate, compressed; valves 1 -nerved ; 

 septum membranous ; style usually slender ; stigma simple. Seeds many, 

 sub-2-seriate, compressed ; cotyledons as in Brassica. DISTRIB. Temp. 

 Europe, Asia, and N. Africa ; species 20. ETYM. $nr\6os and rd^is, from 

 the 2-seriate seeds. Differs from Brassica in the flat pods, membranous 

 valves, minute compressed 2-seriate seeds, and the flowers varying to pink 

 or purplish, which is never the case in Brassica. 



1. D. mura'lis, DC.; stem hispid leafy at the base, leaves sinuate or 

 pinnatifid, scapes slender ascending, pods suberect linear. Sisym'brium, 

 L. Bras'sica brevi'pes, Syme. 



Roadsides and waste places, from Wales and Suffolk southwards ; rare in 

 Scotland and Ireland ; a denizen, Watson ; fl. Aug. -Sept. A small plant. 

 Leaves usually long-petioled. Scapes 6-8 in., slender, ascending. Flowers 

 j; in. diam., yellow. Pods 1-2 in., slender, compressed, narrowed above and 

 below ; valves flat, almost nerveless ; style stout, straight, cylindric ; seeds 

 many, small, compressed. DISTRIB. W. Europe, from Belgium southwards, 

 N. Africa. 



Sub-sp. MURA'LIS proper ; scapes few-leaved, pedicels as long as the expanded 

 flowers, petals 2-3 times as long as the sepals abruptly obovate, style not 

 narrowed below. VAR. 1, muralis proper; annual, stem-leaves few or 0. 

 VAR. 2, Jiabinfflo'nii, Syme ; biennial or perennial, stem-leaves several. 

 S. of England, common, rarer in Scotland ; E. of Ireland, very rare ; a 

 denizen, Watson. 



Sub-sp. VIMIN'EA, DC. (sp.); scapes leafless, pedicels shorter than the ex- 

 panded flowers, petals not twice the length of the sepals obovate gradually 

 narrowed into the claw, style narrowed towards the base. St. Peter Port, 

 Guernsey. 



2. D. tenuifo'lia, DC. ; stem branched leafy, leaves pinnatifid, lobes 

 long narrow, pods suberect linear on very long slender pedicels. Sisym- 

 brium, L.; Sinapis, Sm. ; Brassica, Boiss. 



Roadsides, old walls, &c. from Fife southwards ; a denizen, Watson ; fl. 

 June-Sept. Bushy, glabrous or hispid, glaucous. Jiootstock woody ; 

 branches 1-3 ft. Leaves 3-5 in., lobes distant, very unequal. Flowers 

 J in. diam., yellow. Pods %-% in. distant, linear, nan-owed at both ends ; 

 valves flat ; style stout, straight, oylindric ; seeds many, small, compressed. 

 DlSTBiB. Europe, N. Africa, W. Asia. 



11. DRA'BA, L. WHITLOW-GRASS. 



Herbs, usually small, perennial rarely annual, hoary with stellate down. 

 Leaves entire ; radical rosulate, cauline sessile or 0. Flowers small, race- 

 mose or corymbose, white or yellow. Sepals short, equal at the base. 

 Petals shortly clawed, entire. Pod oblong, rarely linear, compressed ; 

 valves flattish, rarely ribbed ; septum membranous ; stigma simple. Seeds 

 2-seriate, compressed; i'unicles filiform; cotyledons accumbent. DISTRIB. 

 Temp. Arctic and mountain regions, chiefly of N. hemisphere, and Andes 

 of S. America ; a prominent feature in N. Polar regions ; species 80, all 

 very variable. ETYM. SpajSrj, acrid, in allusion to the taste. 



