6 BOTANICAL GAZETTE [yuLy 
Mountain regions. The 
latter (figs. 3-5), based on 
specimens from New Mexico, 
is apparently limited to the 
southern Rocky Mountain 
regions. Both plants were 
originally described from 
specimens on Pinus ponderosa, 
which is their most common 
host. A large collection of 
these plants on P. ponderosa 
and a number of other hosts 
from their respective regions 
shows so few constant dis- 
tinguishing characters by 
Te which the plants from the 
Fic. 3.—R. cryptopoda on Pinus ponderosa: two geographical regions may 
pistillate; New Mexico; reduced one-fourth. readily be separated that it 
—Photograph by G. G. Hepccock. : 
seemed desirable to test them 
out by cultures. Color, branching, thickness of stems, parting of 
flowers, and position of anthers 
on the calyx lobes, characters (29% . 
usually employed to distinguish =, A 
one species from the other, are : 
not always constant in these 
plants from the several regions 
in which they are supposed to 
occur, but apparently merge 
into one form or the other with 
change of habitat, just as is the 
case in any other species having 
a wide distribution and range of 
hosts. In a series of experi- 
ments recently completed by 
the writer and not otherwise 
Fic. 4.—R. cryptopoda on Pinus 
ponderosa: staminate and pistillate; 
mentioned in this paper it has southern Utah. 
3 Piper, CHARLES V., Contrib. U.S. Nat. Herb. 11:222. 1906. 
