FUKTHER STUDIES OF YUCCAS. 209 



through the Tehachapi region, the lower mountains being 

 often densely covered with its large frequently cylindrical 

 panicles or old fruit stalks. The most typical form, as it oc- 

 curs in the Cajon, Tehachapi, and San Luis Obispo regions, is 

 almost always cespitosc, sometimes with eight or ten crowns 

 clustered over a single root, owing to the formation of 

 lateral branches near the base of the main stem, even while 

 this is quite young. After blooming, a given crown dies, 

 but the several heads of these cespitose plants may pro- 

 long the life of the plant through a series of years, until 

 the last of them has flowered. The leaves of this f orni are 

 commonly, though not always, quite rigid. 



The flowers are as variable as in the true Yuccas, ranging 

 from globose to bell-shaped, and there are great individual 

 differences in the degree to which they expand, but they 

 are not typically rotate, as Dr. Engelmann was led to 

 believe by some photographs looking directly into rather 

 widely opened flowers. They differ from those of other 

 species in having the glabrous (but still minutely granu- 

 lated) filaments attached to the lower part of the petals, 

 a character not well shown in the figures in the last Report, 

 so that as they open the stamens are drawn away from the 

 ovary instead of lying in close apposition to it. The small 

 oval anther cells are commonly tipped by a bunch of white 

 hairs, though in specimens observed on the mountain sides 

 above San Luis Obispo these were reduced to one or two 

 on each cell or were apparently entirely wanting, and I have 

 no idea as to their function. On dehiscing, the cells con- 

 tract in such a manner as to expose the pollen freely, but 

 at the same time prevent it in most instances from falling 

 out, as it so frequently does in the true Yuccas. As Riley 

 has already shown,* the pollen of this plant is not loose 

 and powdery, as in Yucca proper, but glutinous. The con- 

 tents of each anther cell, in fact, form a rather consistent 

 two-lobed moist mass, which is held by its lower part but 

 protrudes prominently from the open anther. 



