CRUCIFERiE. 46 



lyrate or pinnate leaves and yellow flowers. Sepals equal at the 

 base. Stigma entire, discoid ; style angular or compressed. Pod 

 oblong or linear, cylindrical, with a slight dorsal compression ; 

 valves very convex, thick at the summit (morticed into the base 

 of the style, Grenier) , having 3-5 longitudinal prominent conti- 

 guous nerves. Seeds in one row, globular, not winged. The pro- 

 minent difference between this genus and Brassica consists in the 

 style, which in Si?iapis is angular or flattened — in Brassica conical 

 or 4-cornered. The strong dorsal nerve of the valve in Brassica, 

 and the three less prominent nerves in Sinajns, may perhaps be 

 another distinctive character, if constant, 



S. arvensis, Lin. Charlock. — e.b. 1748. l.b.s. 116. 



A. 18. C. 82. Lat. 50-61°. Alt. 0-100 yds. Tern. 52-43°. 



Stem erect, branched, hispid. Lower leaves lyrate, or irre- 

 gularly pinnatifid : the upper unequally toothed or sinuated, on 

 shorter stalks, or nearly or quite sessile, usually hairy. Sepals 

 spreading. Pods usually glabrous. 



In fields, often too plenteous. Annual ; June-September. 



YdfY^ glabra. Stem and leaves quite glabrous, the latter en- 

 tire, at least the upper leaves. Fruit cylindrical, torulose, with 

 an angular beak, quite glabrous, and prominently nerved. 



About Chelsea, Battersea, and Kew. 



S. alba, Lin. White Mustard, e.b. 1677. l.b.s. 117. 

 A. 18. C. 60. Lat. 50-59°. Alt. 0-200 yds. Tern. 51-16°. 



Stems erect, branched, glabrous (sometimes hispid). Leaves 

 all lyrate-pinnatifid, glabrous (or hispid), with unequally sinuated 

 or toothed lobes. Sepals spreading. Pods hairy (hispid), with 

 2-3 seeds ; valves shorter than the flattened ensiform beak (sAvord- 

 shaped beak) . Seeds yellowish, finely punctate. 



Fields and waste places. Annual ; June-August. 



Var, Stem and leaves as in the common form ? Sepals spread- 

 ing, partly glabrous. Petals more than twice the length of the 

 sepals. Style flat, not so long as the pod in the matured speci- 

 men. Pod twice as long as in S. alba, and not half so thick, 

 hairy, or bristly, as well as the beak. Seeds ovate, small. 



At Wandsworth Steam-boat Pier a subvariety of this, with the 

 pods not so hairy, and another, with the pod quite glabrous, are 

 found at the same place. 



S. dissecta, Lag. Hort. Madr. This species may perhaps 



