THE YUCCEAE, 85 
frequent vestiges of the marginal characters of both; while 
in the color, shape and texture of the perianth, the slight 
stipe at base of the ovary, the sometimes rather short 
shouldered style, the mostly pendent indehiscent fruit with 
thin exocarp drying about a papery core, and the often 
venously grooved if not truly ruminated seeds, Y. gloriosa 
holds even more nearly the mean between the two species 
named. 
The suggestion of a spontaneous hybrid origin of Y. 
gloriosa offered by this blending in it of tle characters of 
the two other species with which it is most closely associ- 
ated, would be less strong if Y. gloriosa behaved in general 
like a normal species of the genus, if it were of greater 
geographic distribution, or if it occurred in places thor- 
oughly isolated from the assumed parents. 
As has been said, though locally rather abundant, 
Y. gloriosa as a spontaneous plant is limited, so far as is now 
known, to a very restricted region about the Carolina 
and Georgia coast. It is, moreover, a very unusual species 
in its life processes. In the arid region of the Mexican 
table-land, the Yuccas are known to be largely dependent 
for their blooming season upon necessary rainfall, so that 
a given species, though usually fairly regular, may bloom 
in aberrant years at any time between midwinter and mid- 
summer, and the Pronuba moth which serves as pollinator 
appears to show a similar susceptibility to moisture in the 
soil, and commonly emerges from the pupa state synchron- 
ously with the flowering of the Yuccas. Y. gloriosa, how- 
ever, growing in a region where the other Yuccas bloom 
pretty regularly during a rather limited part of the 
spring, when the Pronuba flies, differs from these species 
in flowering usually in late summer and autumn, though 
exceptional flower clusters appear to be developed at almost 
any season of the year, and the only instances that I cer- 
tainly know of in which its fruit has been observed were 
once when early blooming plants cultivated in Washington 
