42 
vi. crucifers : vellEjE. [Diplotaxis. 
pressed beak, stem afid leaves bristly. E. B. t. 1748. Brassica 
Sinapistrum Buiss. : Bentli. 
Corn-fields, too frequent. ©. 5 — 8. — Stem 1 — 2 ft. higli, rough. 
Flowers rather large, yellow. Calyx very spreading. Beak of the pod 
usually empty, sometimes with one seed. 
4. S. alba L. ( white 31.) ; pods hispid turgid shorter and 
slightly narrower than the flat ensiform beak, leaves pin- 
natifid. E. B. t. 1677. Brassica Buiss. : Benth. 
Waste places, frequent in England; more rare in Scotland. ©. 
6,7. — Stem 1 — )4 ft. high, sparingly hairy or glabrous. Leaves 
usually glabrous, the lobes variously cut and toothed, or erose. 
Flowers large, yellow. Well distinguished from the other British 
species by its long, thin beak, which contains a single seed. 
30. Dipi.otaxis Be Cand. Rocket. 
Pod linear, compressed (with usually an empty beak), 2- 
valved ; the valves slightly convex, 1-nerved. Seeds (oval, or 
oblong) in two rows. Calyx patent. — Named from cnr\og, 
double , and ratio, a series, in allusion to the two rows of seeds. 
1. D. tenuifulia DC. (T Vail R.) ; pods shortly beaked erect, 
pedicels spreading, stems erect leafy glabrous somewhat woody 
at the base, leaves lanceolate very acute ^oinnatifid or bipinna- 
tifid glabrous. Sisymbrium L. : E. B. t. 525. Sinapis Br. 
Brassica Boiss. : Benth. 
Old walls and heaps of rubbish about great towns, in the south, 
south-west, and east of England: as London, Bristol, Yarmouth, 
Chester, Tynemouth, and Shields. St. David’s, Fifeshire, but in- 
troduced with ballast. If.. 6 — 9. — Root thick. Slem 1 — ft. 
high, glabrous, almost woody at the base. Flowers large, yellow. 
This plant smells disagreeably. 
2. D. muralis DC. ( Sand R.) ; pods shortly beaked erect, 
pedicels spreading, stem herbaceous hispid spreading leafy only 
at the base, leaves sinuate glabrous. Sisymbrium L. : E. B. 
t. 1090. Sinapis Br. Brassica Boiss.: Benth. 
Sandy barren fields near the sea, in the south and south-west of 
England ; Isle of Thanet, and below Bristol ; also at Tynemouth 
and Shields. Edinburgh and Dunfermline, but not truly wild. ©. 
8, 9. — Very like the preceding, but annual, and much smaller and 
less leafy. 
Tribe X. Yelled;. Pouch with the valves convex; dissepi- 
ment broad. Cot. o>>. (Gen. 31.) 
31. Vella Linn. Cress-rocket. 
Pouch swollen, 2-celled, with a dilated, flat, winged style , 
twice as long as the valves. Seeds 4 in each cell. Cal. erect. 
