26 A Cardon Forest. [ZOE 
of Pleocoma is one of the strongest examples among Coleoptera, 
and is new in this: That while all those others are examples of fol- 
lowing a scent carried upon waves of the atmosphere, there is here 
added the faculty of tracing it to a point well beneath the earth. 
A CARDON FOREST. 
BY T. S. BRANDEGEE. 
Cereus Pringlet was described from specimens collected by Mr. 
Pringle in northwestern Sonora. Later it was collected by Dr. 
Palmer on San Pedro Martir, an island of the Gulf of California, and 
since then has been found to be one of the most abundant of the 
many species of cactus growing in Lower California. There are few 
places between the southern end of the Peninsula and San Quintin, 
where this huge cactus can not be seen. It is called by the Mexi- 
cans “Cardon;” they, however, apply the same name to another 
giant cactus (Cereus pecten-aboriginum), equally as tall and grow- 
ing with C. Pringlet in the southern part of the Peninsula. Along 
the road between La Paz and Triunfo grows one of the largest and 
most striking cardon forests I have seen in Lower California. The 
forest ig composed mainly of plants of C. Pring/ei that cover the 
ground almost entirely for miles, so that when looking down upon 
it not even a bush is visible. The plants are three or four feet or 
more in diameter, branch near the base, and send up a half-dozen of 
nearly erect stems to a height of twenty to forty feet. Itisa strange 
and interesting sight, and in April when the numerous large cream- 
white flowers are in bloom must be very handsome. 
Cereus pecten-aboriginum is not abundant, excepting, perhaps, in 
the Sierra de Laguna; it is more graceful than C. Pring/ez, has 
sharper ribs and a purple tinge to the whole plant, but is most 
readily distinguished by its fruit, which seems often to persist for a 
year. This giant cactus was named by Dr. Engelmann from speci- 
mens of the fruit bought by Dr. Palmer from the Papago Indians ot 
Sonora, who used it as a hair comb, a use that suggested the spe- 
cific name. The fruit covered with stiff yellow spines forms balls 
six inches in diameter, and often many of them growing close to- 
: gether, crowd the tops of the branches. Small plants of this cactus 
grow upon the islands about the harbor of Mazatlan. 
