1913] LAND—EPHEDRA 441 
fewer and fewer until they completely disappear at 2200 meters. 
Rarely plants are found growing in the scanty bowlder-strewn soil 
on ledges along the face of the limestone walls of the box cafion. 
In one instance a small clump was seen on the extreme edge of the 
great cliff (fig. 1) which towers above the cafion floor. In the 
coarse limestone talus at its base were a few plants, much battered 
by falling stones. This cliff, rising almost to the vertical range 
of Ephedra is capped by a steep ridge of the coarse friable sand- 
Fic. 2.—Ephedra on sandstone talus near lower limiting altitude; dead Pinus 
edulis in foreground; a typical situation. 
stone of the lower cafion. Here also were a few small clumps of 
depauperate plants. Ephedra was not found on the relatively 
moist, well-wooded north slopes nor in the cafons of adjacent 
watercourses, but the rough nature of the country made extended 
search somewhat difficult. 
Some plants reach a height of 2.5 meters, and below the first 
branching, which is usually at the surface of the soil, may attain a 
diameter of 1ocm. The largest trunk found (fig. 3) had a diameter 
of 5 cm. just above the first fork. The greatest number of seasonal 
