146 



BBASSICACEAE. 



septum; endosperm none; cotyledons incumbent, aceumbent or condupli- 

 cate. About 200 genera and 1800 species, of wide geographic distribution. 



Fruit a silicle, little, if any, longer than wide, orbicular, globose 

 Silicle flattened at right angles to the septum. 

 Seed solitary in each cell of the silicle. 

 Silicles smooth, orbicular to ovate. 

 Silicles rugose or tubercled, didymous. 

 Seeds several in each cell of the winged silicle. 

 Silicle flattened parallel to the septum. 

 Fruit an elongated silique. 



Silique dehiscent into two valves. 

 Plants densely stellate-pubescent. 

 Plants not stellate-pubescent. 

 Silique not beaked. 

 Silique distinctly beaked. 



Silique terete ; seeds in a single row. 



Silique conic-beaked, its valves 1-nerved. 

 Silique stout-beaked, its valves 3-5-nerved. 

 Silique flattened ; seeds in 2 rows. 

 Silique indebiscent. 



Silique of 2 joints, separating when ripe. 

 Silique constricted between the seeds, not jointed. 

 Fruit a triangular obcordate silicle. 



or oblong. 



1. Lepidium. 



2. Carara. 



3. Thlaspi. 



4. Koniga. 



5. Microstigma. 



6. Erysimum. 



7. Brassica. 



8. Sin apis. 



9. Diplotaxis. 



10. CaMle. 



11. Raphanus. 



12. Bursa. 



1. LEPIDIUM [Tourn.] L. 

 Erect or rarely diffuse herbs, with pinnatifid lobed or entire leaves and 

 racemose white or whitish flowers. Stamens often fewer than 6. Petals short, 

 sometimes none. Silicles oblong or obovate, flattened contrary to the partition, 

 winged or wingless; valves keeled, dehiscent. Seeds solitary in each cell, 

 flattened; cotyledons incumbent or rarely aceumbent. [Greek, a little scale, 

 from the flat scale-like pods.] About 65 species, widely distributed. Type 

 species: Lepidium latifolium L. 



1. Lepidium virginicum L. 



Wild Pepper-grass. (Fig. 168.) 

 Annual; stem erect, 2° high or 

 less, glabrous. Basal leaves obo- 

 vate or spatulate in outline, gen- 

 erally with a large terminal lobe 

 and numerous small lateral ones, 

 all dentate, glabrous or slightly 

 pubescent ; stem-leaves lanceolate 

 or oblong-linear, sessile, or the 

 lower stalked; flowers about 1" 

 broad, white; petals generally pres- 

 ent, sometimes wanting in the later 

 flowers; pedicels slender, spread- 

 ing, 2"-3" long in fruit; pod flat, 

 short-oval or orbicular, minutely 

 winged above; cotyledons aceum- 

 bent. 



Common in waste and cultivated 

 grounds. Naturalized from North 

 America or the West Indies. Flowers 

 nearly throughout the year. [L. 

 apetalum of Millspaugh.] 



