JOURNAL 
The New York Botanical Garden 
VoL. IX. — November, 1908. No. 107. 
A NEW GENUS OF CACTACEAE. 
The gigantic cactus of Arizona and adjacent regions, known in 
its home by the common name sahuaro, is one of the most re- 
markable of plants and the most striking element in the desert 
vegetation of the southwest. As pointed out by Dr. D. T. Mac- 
Dougal, it was probably first observed by Europeans about 1540, 
when the expedition of Coronado passed through the region 
which it inhabits ; Onate in 1604 passed through the valley of 
the Bill Williams Fork of the Colorado River in Arizona and 
noted the plant, and his account is probably the earliest printed 
record of it (see Journ. N. Y. Bot. Gard. 6: 129-130). While 
known to earlier explorers from the Atlantic eee) the first 
specimens of this interesting plant were collected on the expedi- 
tion of Lieut. W. H. Emory, a military reconnoissance from Fort 
Leavenworth in Missouri to San Diego in California, during the 
autumn of 1846, and the plant is frequently referred to in his 
report. These specimens were sent to Dr. George Engelmann at 
St. Louis and after a study of them he gave this cactus the 
botanical name Cereus giganteus. 
e plant grows on hillsides in southern Arizona, south- 
eastern California and northern and central Sonora, sometimes 
reaching a height of sixty feet, branching at from twelve to 
twenty feet above the ground. Travelers through these regions 
are always impressed by its very unusual form, and many 
thousands of people have become familiar with it since three 
plants were brought to the New York Botanical Garden by Dr. 
MacDougal in the spring of 1902, where they have since been 
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