188 FLOBA OF -PHILADELPHIA. 



Seeds flat, wingless, or winged. 



Siliques 4-angled, the valves keeled; flowers yellow. 



11. Barbarea. 

 Siliques flat or flattish. 



Valves of the silique nerveless. 



Stems leafy below or throughout. 13. Cardamine. 

 Stems leafless below, 2-4 leaved above. 



14. Dentaria. 

 Valves of the silique 1-nerved or veiny, not elastically de- 

 hiscent. 24. Arabis. 

 b. Silique produced into a beak beyond the valves. 

 Beak eonic, very short in No; 8. 



Silique terete; seeds in 1 row. 8. Brassica. 



Silique flat; seeds in 2 rows. 9. Diplotaxis. 



Beak flat, sword-shaped. 7. Sinapis. 



' 2. Silique elliptic or oblong, very flat, 2-3 times as long as broad, clearly 

 stipitate. 15. Lunaria. 



j^-Pgd an orbicular globose or oblong siliele, or but little more than twice 

 as long as wide. 



a. Siliele globose, or flattened parallel with the septum. 



Siliele globose, or terete-oblong, little or not at all compressed. 

 Seeds minute, round, , not flattened, in 2 rows in each cell. 



12. Boripa. 

 Seeds flat; siliele inflated; plants stellate-pubescent. 



16. Lesquerella. 

 Siliele compressed or flat, many-seeded. 21. Draba. 



Siliele compressed or flat, many-seeded. 



Flowers yellow. » 26. Alyssum. 



Flowers white. 27. Koniga, 



Siliele pear-shaped or obovoid, many^seeded. 



18. Camelina. 



b. Siliele flattened at right, angles to the narrow septum. 



Seeds several in each cell of the siliele. 



Siliele triangular, obcuneate. 17. Bursa. 



Siliele oblong or orbicular, winged all around. 



• 3. Thlaspi. 

 Seeds solitary in each cell, compressed. 1. Lepidium. 



**Pod indehiscent, short or elongated. 



Pod broader than long, more or less didymous. 2. Coronopm. 



Pod globose, reticulated. 19. NesUa. 



Pod elongated. 



Pod of 2 joints, separating at maturity. 



Lower joint of pod seedless or 2-4-seeded; cotyledons condupli- 



cate. 20. Bapistrum. 



Lower joint of pod 1-seeded; cotyledons accumbent. 



6. Cakile. 

 Pod constricted between the seeds, not jointed, beaked. 



10. Baphanus. 



1. LEPIDIUM L. Peppergrass. 



Stem-leaves clasping by an auriculate base. 



Pods broadly ovate, winged. 1. L. campestre. 



Pods wingless, broader than long. 2. L. Draba. 



Stem-leaves petioled or sessile, not clasping. 



Pods and seeds entirely wingless; petals none. 3. L. ruderale. 



Pods slightly winged above, orbicular or oval, about 2 mm. broad; 

 petals present or none. 

 Cotyledons accumbent ; petals generally present. 4. L. Virgmieum. 

 Cotyledons incumbent; petals minute or wanting. 



5. L. apetalum. 



