DISSEMINATION AND LEAF REFLEXION OF yucca. 105 
evidently partially cut through and that which remains is 
dry and brittle and breaks off by the weight of the cluster 
(Plate 47, fig. 3, a). 
The seeds of the old dried fruits are frequently ana 
by the ravages of a beetle which burrows in the dried pulp 
and seeds. Many of the seeds, however, remain uninjured 
and apparently long retain their power of germination. 
It is probable that the other Sarcoyuccas show the same 
leaf reflexion that occurs in aloifolia, but the periods of 
growth and other details may vary. So far as can be 
determined from photographs and drawings of the var- 
ious species of Yucca, it appears that of the Sarcoyuccas, 
baccata,* Guatemalensis,t Schottii,t australis § and macro- 
carpa || show this periodic leaf refiexing. Other species 
may show the same phenomena but no data are at hand 
from which this can be determined. 
Of the Clistoyuccas, brevifolia { evidently shows beauti- 
fully this periodic leaf reflexing, the old trunk remaining 
covered by the persistent, reflexed, dried up leaves which 
in age become closely appressed against the trunk. 
Among the Chaenoyuccas, Y. elata, a stemmed species 
which grows to a considerable height forming a rather 
large tree in Arizona, is particularly interesting from the 
fact that here among the capsular Yuccas according to Dr. 
Trelease ** we find a counterpart of aloifolia in that the 
* Trelease, Wm., ‘“‘Notes and Observations. 1. Detail Illustrations, 
of Yucca,’’ 1. c., Plate 2. 
+ Trelease, ‘‘ Further Studies of Yuccas and their Pollination,” LiiGes 
Plates 1 and 2. 
t Trelease, as in last citation, Plate 3. 
§ Trelease, as in last citation, Plates 4 and 5. 
| Merriam, C. Hart, “‘ Notes on the Geographical and Vertical Dis- 
tribution of Cactuses, Yuccas, and Agave, in the Deserts and Desert 
Ranges of Southern California, Southern Nevada, Northwestern Arizona 
and Southwestern Utah.”? In “The Death Valley Expedition; A Biologi- 
cal Survey of Parts of California, Nevada, Arizona, and Utah. Part Hi,” 
North American Fauna, No. 7, p. 358, Plate 14. 
q Trelease, as above, Plates 6, 7 and 8. 
** Trelease, Wm., ‘“ Further Studies of Yuccas and their Pollination,” 
l.c., p. 202, Plate 10.— Also “ Detail Illustrations of Yucca,” 1.c., Plate 9. 
