ANALOGIES AND AFFINITIES. 47 



ease witli wliicli its typical flower- aud fruit-structure may 

 be defined and recognized. Haying pointed out the tetra- 

 sepalous calyx, the cruciform-tetrapetalous corolla, the six 

 tetradynamous stamens and the distinctively siliquose fruit, 

 he must now take care that he select his illustrations from 

 gardens, fields or waste lands where either under cultivation 

 or spontaneously the Old AVorld plants abound. ^^ hen, 

 under these precautions, he has impressed upon the minds 

 of the beginners, a clear notion of what cruciferous plants, 

 as to their anthology, should be like, he ma/ send them 

 forth to the woods or untilled hillsides where native crucifei's 

 prevail, to collect these. The mission may be nearly fruit- 

 less. The most common and beautiful of our indigenous 

 genera and species will escape their recognition. The 

 streptanthi, if past flowering and in fruit, may get gathered, 

 for their pods are true silicpes; but their colored calyces 

 variously distorted, the uncruciform corollas, and the any- 

 thing but tetradynamous stamens are all delusive. ihe 

 charming lace-pods (T%sanoc«rpi/s), whose flowers are too 

 minute for field examination, have the most ornamental of 

 fruits, but these are plano-convex broadly and fenestrately 

 winged samaras, presenting to the unpractised eye not the 

 remotest hint of either silique or silicle. While Athysanus 

 and Hderodraha ' have indehiscent fruits not quite so unlike 

 proper silicles, their six stamens are not only of exactly equal 

 length, but are disposed three in a line on either side of the 

 minute and flatly compressed ovary. Tvopnlocannm with 

 a good cruciform flower will confront the tyro with a pod 

 which, while looking like a silique at first, opens from the top 

 and has no partition within. Along the seashore Calale will 

 present its own anomalous fruits which will scarc^ely fail to 

 be mistaken for large and well developed flower-buds. 



In a flora where, as in that of California, exceptional types 

 of floral and carpal structure predominate, the test of flavor 

 in the case of the Crucif erre, may well be brought m to the 



See Bull. Calif. Aead. i. 71-73 



