238 BARTRAM: BOTANIZING IN SOUTHERN ARIZONA 
least fifteen miles away instead of under five miles as we had 
fondly imagined. The horses are willing and capable of covering 
thirty miles or more in a day without discomfort, but the first 
days experience proved conclusively that the one indispensable 
article of equipment was a good canteen; for, excepting a few 
canyons in the Catalina Range reaching well back into the forested 
and snow-covered slopes, water is never available. The higher 
peaks are heavily snow-capped during most of the winter months, 
although snow rarely descends to the level of the plains. After 
a rainy night in January it is not unusual to see the snow line 
across the slopes as straight as though it had been drawn with 
a ruler. In the sheltered canyons where snow rarely falls and 
never persists we found many flowering plants in early January 
which were materialy increased in number and variety with 
each succeeding week. Many plants are distributed generally 
over entire ranges but in each canyon, walled in by the steep 
arid intervening ridges, we found some species that were wanting 
in every other locality we visited. 
Sabino Canyon in the Santa Catalina Mountains, distant 
some sixteen miles from Tucson, is one that we happened to 
reach quite frequently and will serve nicely as an example of 
these interesting localities. Leaving early we drive across the 
plains through miles of pungent greasewood with its curiously 
folded leaves and ‘bright yellow flowers, which even now are 
giving way to the little felted spheres of fruit. Thickets of 
cholla, six or eight feet high, varying in color from pale green to 
ruddy brown and brightened with pendant clusters of orange 
colored fruit, glow in the early sunlight. Cirsium neomexicanum, 
Lesquerella Fendleri, and Baileya multiradiata are in bloom along 
the roadsides, the stiff wands of old fruit bend over colonies of 
gray-green Atriplex canescens, and here and there an occasional 
Yucca elata lifts its brown panicle of old fruit above the shrub 
level. In a broad belt along the base of the mountains the 
sahuaro gives a grass green tinge to the foothills ten miles away 
where the arroyos are marked by wavering lines of mesquite and 
desert willow. The hot rocky slopes flanking the mouth of 
the canyon are spotted with Opuntia Bigelovii, glistening like 
spicules of glass in the brilliant sunshine and undoubtedly the 
most vicious of all the chollas. A carpet of detached joints 
covers the ground about every plant, and woe to the unwary 
