NEGLECTED GENERIC TYPES. 209 
How clearly distinet from true Cleome our far-western 
allies of that genus are, was well enough shown by Nuttall 
in 1818; and the point was again emphasized by him in 
1834. Meanwhile, in 1824 the elder De Candolle, certainly 
to be ranked as one of the great masters of botanical tax- 
onomy, had adopted the genus heartily, at the same time 
assigning it a tenable name, in place of the original but 
homonymous Atalanta of Nuttall. 
The characters of the genus are so numerous that I can 
only excuse those of our botanists who have ignored it, on 
the ground of the paucity of our capparids on the whole, 
together with the fact that the Peritomas, occupying their 
own distinct section of our territory, are never seen growing 
along side the Cleomes, and so their differences, even of 
general habit and aspect, have not drawn the attention of 
those without field experience both southward where 
Cleome occurs, and far-westward in the region of Peritoma. 
The most obvious character of Peritoma as compared with 
the older genus is its synsepalous calyx. Equally striking, 
and also even more notably characteristic, are its sessile 
petals; those of Cleome being long-unguiculate. And again, 
while in Cleome the four petals on their long slender stalks 
are turned to one side, so as to stand in a row (as in Gaura 
when compared with (nothera), those of Peritoma radiate 
as from the center, as sessile petals in such flowers are almost 
obliged to radiate. So that, on the whole, even the corollas 
of these two genera differ, those of each from those of the 
other, with the difference which distinguishes regular and 
irregular corollas. The name Peritoma itself, however, calls 
attention to the strong character of the calyx, which, con- 
sisting of a tube and teeth or segments, is deciduous by a 
sort of cireumscission of the tube near its base. 
The species of this genus are not numerous, and are 
named as follows: 
