210 PITTONIA. 
P. sERRULATUM, DC. Prodr. i, 237. Cleome serrulata, 
Pursh, Fl. ii, 441. Atalanta serrulata, Nutt. Gen. ii, 73. A 
common large and showy species, of the Rocky Mountain 
plains and foothills originally, but of late years extending 
its range eastward to Illinois and Wisconsin. 
P. iNoRNATUM. Cleome inornata, Greene, Pitt. iv, 16. A 
small species of southwestern Colorado, at present little 
known. 
P. AUREUM, Nutt. Journ. Philad. Acad. vii, 15. From 
the plains of the Platte to those of Lewis River, according to 
Nuttall. The species has not been recognized latterly, nor 
do I know it, yet have I more faith in Nuttall's knowledge 
and judgment of western plants than I have in those who 
suppress his species. Many have confused this with the 
next. 
P. rurEUuM, Raf. Sylv. Tellur. 112. Cleome lutea, Hook. 
Fl i, 70, t. 25. Of wide dissemination on alkaline desert 
plains beyond the Rocky Mountains. 
CELOME. 
In the Cleome platycarpa of Torrey we are furnished with 
another decidedly good if not strongly characterized generic 
type. Here we have a calyx at the opposite extreme from 
that of the synsepalous genus Peritoma; for its sepals are 
not only distinct, but almost filiform, and widely spreading 
from their very base. The corolla, however, is as far from 
that of Cleome ascan well be. The petals, though spatulate, 
are not the least inclined to one side, but are radiant as in 
Peritoma, though apparently more spreading. The fruit is 
altogether peculiar among those of our capparids in that it 
is very broad and flat, presenting the seeds in two perfectly 
