108 CRUCIFERACEAE (MUSTARD FAMILY) 



QQ. Pod flattened parallel to the partition, 12-31 mm. long; mostly not 



ditch plants. CARDAMINE (p. 113) 



Q Q Q. Pod flattened at right angles to the partition, 6-10 mm. long; plants 



of rather dry places. SMELOWSKIA (p. 115) 



OO. At least the leaves of the upper half of the stem entire or merely toothed 



or serrate. 



R. Pod 3 cm. or less long. ARABIS (p. 115) 



RR. Pod 3.5 cm. or more long. 



S. Petals undulate-crisped, but little longer than the sepals, the blade 

 merely a wide extension of the claw. CAULANTHUS (p. no) 



SS. Petals plane, much longer than the sepals or else the blade well de- 

 veloped. THELYPODIUM (p. no) 

 NN. All of the leaves from entire to shallowly lobed, none pinnatifid. 

 T. Mature pod 2.5 cm. or less long. 

 U. Pod flattened parallel to the partition. 



V. Leaves all petioled; valves veinless. CARDAMINE (p. 113) 



W. Stem leaves sessile. 



W. Valves of the pod veinless; stem leaves not clasping. DRABA (p. 115) 

 WW. Valves i-veined; stem leaves clasping in most species. 



ARABIS (p. 115) 



UU. Pod terete or angular or hardly flattened. 

 X. Plant glabrous. 



Y. Pod 2-celled by a transverse constriction. mdehiscent. W. 

 (Arabic name.) Cakile edentula (SEA ROCKET) 



YY. Pod 2-celled by a longitudinal wall, dehiscent. 



THELYPODIUM (p. no) 



XX. Plant more or less pubescent with branched hairs. 

 Z. Flowers in a globular head. C. (Honor of F. G. DeBray, a French 

 count.) Braya humilis (LOW ROCK CRESS) 



ZZ. Flowers in an elongated raceme. W. (Gk. stenos = narrow, 

 phragma = a partition; referring to the partition in the pod.) 



Stenophragma thaliana (MOUSE -EAR CRESS) 

 TT. Mature pod more than 2.5 cm. long. 



a. Caudex stout and branching, the branches densely clothed with the 

 persistent petioles of former seasons. E. (Honor of W. E. Parry, an 

 English explorer.) Parrya menziesii 



aa. Caudex none or not so clothed. 



b. Petals flat; anthers short, subcordate. ARABIS (p. 115) 



bb. Petals twisted; anthers long, sagittate. STREPTANTHUS (p. in) 



GROUP 2 (with short pods) 

 A. Flowers yellow. 



B. Pod flattened parallel to the partition. 



C. Pod orbicular; seeds 2 in each cell of the pod. W. E. (Gk. a = against, lyssa 

 = madness; one was reputed a remedy for hydrophobia.) 



Alyssum alyssoides (YELLOW ALYSSUM) 



CC. Pod elliptic to oblong; seeds 3 or more in each cell. DRABA (p. 115) 



BB. Pod flattened at right angles to the partition. 



