WEST AMERICAlir OEUCIFEB^. 85 



larity of the calyx, I readily refer this plant here, notwithstand- 

 ing that its foliage and bracts no less than its narrow pods 

 wonld relegate it to the next genus, were not the calycine charac- 

 ters to be regarded the most essential in deciding the genus. 



For a considerable group of species, among which those that 

 I regard as most typical of a genus are mainly Californian and 

 biennial, I propose the generic name plbiocardia, in allusion to 

 what gives them an aspect decidedly their own when compared 

 with members of Euclisia, namely, the presence of large more 

 or less rounded sessile and cordate bracts — disciform organs — 

 taking the place of ordinary leaves upon the flowering branches, 

 often numerously subtending the racemes. By this striking 

 vegetative character these plants may seem related to Euclisia, 

 in some such degree as the Old World Lepidium perfoliatum and 

 its kindred, with their pinnatisect true leaves, and round disci- 

 form phyllodes subtending the racemes, are related to more 

 genuine Lepidium. But these with the "perfoliate" discs in 

 place of upper cauline leaves were segregated from Lepidium 

 under the name Candis by Adanson, and have been maintained 

 in that rank by later authors under one or more later names. I 

 should not hesitate to accept them as a genus. 



But this vegetative character is not essential to Plbiocakdia. 

 While it suggested the generic name I admit to the genus a few 

 species that have not that mark; and even the original species of 

 Streptanthus have broad and cordate-clasping upper leaves, 

 though the transition to them is not abrupt as it is in the Cali- 

 fornian plants of the proposed new genus. 



The essential characters of Plbiocardia are those of flower 

 and fruit. Its calyx is (1) regular, not bilabiate as in Euclisia, 

 (2) closely fitting up to the corolla and stamens, not distended 

 and as it were inflated between base and summit; (3) tips of 

 sepals dilated, recurved and scarious-edged as in neither Strep- 

 tanthus nor Euclisia \ (4) petals not radiating cruciformly as in 

 Streptanthus but diverging in opposite pairs as in Euclisia; (5) 

 stamens in 3 unequal pairs, all distinct as in Streptanthus ( in 



