Io8 CRUCIFERACEAE (MUSTARD FAMILY) 



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

 ditch plants. CARDAMINE (p. 113) 



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

 of rather dry places. SMELOWSKIA (p. 115) 



00. 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. CAULANTHTTS (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. ' 

 IT. 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 con.striction indehiscent. W. ^ 

 (Arabic name.) Cakile edentula (sEA kocb^et) 



YY. Pod 2-ceUed 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 ckess) 



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



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



Stenophragma thallana (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. STREPTANTHTJS (p. in) 



GROUP 2 (with short pods) 



A. Flowers yellow. 

 B. Pod flattened parallel to the partition. 

 C. Pod orbicular; seeds 2 in each ceU of the pod. W. E. — (Gk. a = against, Zyi.so 

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



Alyssum alyssoides (yellow ALYSsmi) 

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



BB. Pod flattened a,t right angles to the partition. 



