Kunzé: THe DeEsERT FLORA OF PHOENIX, ARIZONA 307 
after the rains of August, should there be any, it is again clothed 
in verdure, flower and fruit. Such is the case with many Arizona 
plants of the Sonoran flora. 
Holacantha Emoryi, the crucifixion thorn of Mexicans, although 
not an evergreen shrub in the strict sense, being leafless and the 
thorniest of ugly thorns, is nevertheless green the year round. 
Every branch is clothed with sharp rounded thorns from one to 
four inches long. Its clusters of orange and red flowers closely 
attached to the axils or bifurcation of the thorns, appear in May 
and June, followed by fruit in July and August. Flowering 
branches are preserved for the use of tourists, and offered for sale 
in the curio shops of Arizona. The size and thickness of the 
thorns remind one of G/leditsta triacanthos. This shrub grows 
from two to six feet or more in height. 
Artemisia tridentata, the well-known sagebrush of the desert, 
with the minute grayish-green leaves, attracts much less attention 
in appearance than size. It grows from three to eight feet or 
more in height according to soil. In the more sandy parts of the 
desert, it provides shelter for many tender if not more useful plants. 
The small Cactus Grahami thrives in its shade, and the slender, 
fragile branches of Cereus Greggu find a support growing through 
its mass of slim branches. 
Another Artemisia, apparently undescribed, is much hand- 
somer, of a brighter green color and with large leaves. It affects 
the region of the cactus, growing in more rocky and sandy soil. 
Its height is from one and one half to two and one half feet. 
Ephedra trifurcata, or ‘‘cafiatilla’”’ of the Mexicans, is a strange 
looking shrub, leafless and with sheathed branches like Egucsetum. 
Its branches are closely crowded, of the thickness of a straw or less, 
and of a grayish-green color. It is a shrub from three to five feet 
high, and very many stems are given off from a common root. It 
affects the arroyos and swales of the desert in preference to drier 
situations. The Mexicans use this plant extensively in the form 
of decoction for specific urethritis, and hold it in high esteem. 
Ephedra antisyphilitica, a closely allied species found nearer to 
the Mexican boundary and further south, is also much used in 
Mexico for similar purposes and as a diuretic. This plant is two 
feet in height. 
PHOENIX, ARIZONA. 
