CRUCIFERACEAE (MUSTARD FAMILY) 107 



E. Leaves awl-shaped; plants aquatic. GROUP 2, P (p. 108) 



EE. Leaves not awl-shaped; plants mostly terrestrial. 

 F. Pod 3 or more times as long as wide including its stipe and beak. 



GROUP 1 (p. 107) 

 FF. Pod less than 3 times as long as wide including its stipe and bealc. 



GROUP 2 (p. 108) 



GROUP L (with long pods) 

 A. Petals yellow. 



B. Pod borne on a stipe I cm. or more long. STANLEYA (p. no) 



BB. Pod without a stipe, or with a very short one. 

 C. Leaves entire or merely serrate. 

 D. Seeds in 2 rows in each cell of the pod; mature pod 3-14 mm. long. 



DRABA (p. lis) 

 DD. Seeds in i row in each cell of the pod; mature pod 1.5-10 cm. long (or 

 as short as i cm. in Erysimum cheiranthoiies) . 

 E. Pod torulose; valves veinless or faintly i-veined; petals 4-6 mm. long. 

 E. — {Crambe is another genus; Gk. schoenos = a reed; hence a reed-like 

 Crambe.) Schoenocrambe linifolia (plains aruSTARD) 



EE. Pod not torulose; valves strongly keeled by the prominent mid vein; petals 

 6-2S mm. long (except E. cheiranthoiies). ERYSIMUM (p. 115) 



CC. At least some of the leaves lobed or pinnatifid or pinnately compound. 

 F. Most of the leaves of the upper J of the stem entire or merely serrate. 

 G. Pod not beaked, 5-12.5 cm. long when mature. (See EE.) 

 GG. Pod beaked, 2 cm. or less long when mature. BRASSICA (p. 112) 



FF. Most of the leaves of the upper i of the stem lobed or pinnatifid or pin- 

 nately compound. 

 H. Pod indehiscent; seeds 2-10. RAPHANUS (p. 112) 



HH. Pod dehiscent; seeds usually more numerous. 

 I. Pod beakless or the beak very short and thick. 

 J. Seeds flat; leaves lyrate-pinnatifid. BARB AREA (p. 112) 



JJ. Seeds not flat; leaves not or hardly lyrate-pinnatifid. 

 K. Seeds in I row in each cell of the pod; valves of the pod mostly 3-veined; 

 pubescence simple or none. SISYMBRIUM (p. in) 



KK. Seeds in 2 rows in each cell of the pod; valves of the pod i-veined ; 

 ' pubescence often forked or stellate. RORIPA (p. 113) 



n. Pod with an abruptly slender or a flat beak at least \ as long as the fertile 

 portion. BRASSICA (p. 112) 



AA. Petals either none or of some color other than yellow. 

 L. Leaves temately- or palmately-lobed or -laciniate or -divided. 



DENTARIA (p. 114) 

 LL. Leaves pinnately-toothed to -compound, or entire and pinnately-veined. 

 M. Pod borne on a stipe i cm. or more long. STANLEYA (p. no) 



MM. Pod without a stipe or with a very short one. 

 N. Some of the leaves pinnatifid. 

 O. Stem leaves all pinnatifid. 

 P. Pod indehiscent, not longitudinally 2-celled. RAPHANUS (p. 112) 



PP. Pod dehiscent, longitudinally 2-celled. 

 Q. Pod terete, 1-16 mm. long; plants of ditches. RORIPA (p. 113) 



