36 CRUCIFER^E. 



3 Nasturtium. Pods short, turgid, little compressed, nerveless. 



4 Roripa. Pods terete or nearly so, with nearly or quite nerveless, thin 



valves. 



5 Barbarea. Pods linear, elongated, somewhat tetragonal : seeds in I 



row in each cell. 



6 Arabis. Pods linear with more or less 1-nerved flat valves and thin 



partition : seeds in 1 row in each cell, flattened and more or less winged. 



* * * Pods oblong or linear, compressed parallel to the partition, sessile. 



7 Streptanthus. Pods oblong to narrowly linear, compressed parallel to 



the partition, sessile upon the enlarged receptacle : valves flat, nerve- 

 less, seeds flat, more or less winged : cotyledons accumbent. 



8 Caulanthus. Pods narrowly linear, somewhat flattened or subterete, 



sessile : valves 1-nerved and often reticulate-veined : cotyledons incum- 

 bent. 



9 Dentaria. Pods linear, with nerveless flat valves and nerveless 



partition : seeds in 1 row in each cell wingless. 



10 Cardamine. Pod linear with thin flat nerveless valves, and wingless 

 seeds in 1 row in each cell. 



TRIBE n. Pod a silicle, 2-celled, completely dehiscent, strongly 

 compressed parallel to the broad partition or very turgid with 

 broad partition and almost hemispherical valves, or didymous, or 

 strongly obcompressed. Pubescence stellate. 



* Pods strongly compressed parallel to the broad partition. 



11 Platyspermum. Pods suborbicular, very strongly compressed parallel 

 to the broad partition : seeds in 2 rows in each cell, broadly winged. 



* * Pods turgid with broad partition. 



12 Lesquerella. Pods subglobose: partition suborbicular: seeds flattened 



* * * Pods didymous w r ith narrow partition. 



13 Physaria. Silicle didymous or obcompressed, partition narrow -ellip- 

 tical : cells several-seeded. 



* ** * Fruit orbicular or nearly so, 2-celled, dehiscent, 2-several-seeded : 

 filaments often dilated and toothed or appendaged near the base. 



14 Psilonema. Capsule with valves convex, pubescence stellate. 



* * * * Fruit oblong elliptic or lanceolate, rarely linear, 2-celled, 

 dehiscent, 2-sveral-seeded : stamens unappendaged. 



15 Erophila. Flowers white : petals deeply 2-lobed or parted : pods linear 

 to oblong, many-seeded . 



H> Draba. Sepals short and broad, equal at the base : petals entire or 

 emarginate. 



17 Cochlearia. Pods (in ours) very turgid and appearing obcompressed, 

 with distinctly 1-nerved valves. 



TRIBE in. Pods longitudinally 2-celled, dehiscent, from linear 

 to lance-oblong or elliptic, always longer than broad. 



18 Sophia. Pods ascending or somewhat spreading, on slender pedicels, 

 oblong-linear, subterete, less than an inch long. 



19 Erysimum. Pods subsessile, erect, appressed to the rachis, subulate. 



20 Smelowskia. Pods lanceolate to lance-oblong, more or less obcom- 



pressed with sharply keeled valves. 



21 Sehoeiiocrambe. Pods slender, terete, somewhat torulose. 



