CKUCIFERJE 



311 



AA. Fruit a silicic (short and broad). 



B. Partition in the pod parallel to the sides 3. Alyssum 



BB. Partition crosswise the pod. 



c. Pod obcordate, many-seeded 4. Capsella 



cc. Pod orbicular, 2-seeded 3. Lepidium 



1. BRASSICA. MUSTARD. 



Erect branchy herbs, mostly annual, with more or less lyrate lower 

 leaves, and small yellow flowers in racemes or panicles: petals clawed or 

 narrowed below, the limbs spreading horizontally: silique narrow, 

 cylindrical or 4-angled, the valves 1-5-nerved and the seeds in 1 

 row in each locule. Cabbage, cauliflower, and turnip also belong to 

 this genus. The three following are common weeds introduced from 

 Europe. 



B. nigra, Koch. Slack mustard. Fig. 459. Leaves pinnatifid, 

 somewhat hairy: pod short, strongly 4-angled, not hairy. Mustard 

 (flour) comes largely from this species. 



B. alba, Boiss. White mustard. Leaves pinnatifid and rough- 

 hairy : pods rather slender, hairy,but only the lower part seed-bearing. 



B. Sinapistrum, Boiss. Charlock. Leaves strongly toothed: pod 

 knotty, hairy or smooth, the upper third indehiscent and 2-edged. 



2. BARBAKEA. WINTER CRESS. 



Low herbs, blooming in early spring, with many small light 

 yellow flowers, and lyrate leaves with the terminal division much the Brassica 

 largest: pod cylindrical or somewhat 4-angled, the valves having nigra. 

 a strong mid vein: seeds in a single row. 



B. vulgaris, R. Br. Common winter cress. Yellow rocket. Biennial, 

 about 1 ft. high, with smooth foliage and flowers in elongating clusters: 

 lower leaves lyrate, upper ones cut or merely toothed. Low grounds. 



3. ALYSSUM. ALYSSUM. 



Small plants, mostly trailing, with entire and small 

 leaves: pod small, orbicular, one or two seeds in each 

 locule: flowers in elongating racemes. 



A. maritimum, Linn. Sweet alyssum of the gardens 

 (from Europe). Fig. 460. Annual, producing a profusion 

 of small white, fragrant flowers. 



4. CAPSELLA. SHEPHERD'S PURSE. 



Low short-lived annuals, with very small white flow- 

 ers in racemes: pod obcordate or inversely triangular, the 

 partition running across the narrow diameter, containing 

 several seeds. 



C. Bursa-pastdris, Moench. Com,mon shepherd's 

 purse. Fig. 259. One of the commonest little weeds: 

 root leaves pinnatifid or strong-toothed, in a rosette, the stem leaves arrow- 

 shaped. Europe. 



459. 



460. Alyssum 

 maritimum. 



