i 7 8 



THE CACTACEAE. 



the changes we see in certain other genera such as Cephalocereus, Arrojadoa, and to a less 

 extent in Carnegiea, on account of which both this species and Carnegiea gigantea have 

 been referred by some authors to the genus Pilocereus. 



Lophocereus schottii inhabits parts of western Mexico and southern Arizona, which 

 have great aridity, but it usually grows in colonies and in this way seems to withstand the 

 rigor of the desert. Its range is more extensive than that of most cacti and it shows con- 

 siderable variability. Three species of Lophocereus have been described, but appear to be 

 merely geographical races of this one. 



Illustrations: MacDougal, Bot. N. Amer. Des. pi. 8; Cact. Mex. Bound, pi. 74, f. 16, 

 as Cereus schottii; Schumann, Gesamtb. Kakteen f. 37, 38, as Pilocereus schottii; Orcutt, 

 Gard. and For. 4: f. 69, as C. sargentianus; Monatsschr. Kakteenk. 5: 86, as P. sargentianus. 



Fig. 251. — Lophocereus schottii. 



Figure 251 is from a photograph obtained by Edward Palmer near Guaymas, Sonora; 

 figure 252 shows a section through the upper part of a flowering stem collected by Dr. 

 Rose at Abreojos Point, Lower California, in 191 1; figure 253 shows a flower of a plant 

 brought by Dr. MacDougal from Arizona to the New York Botanical Garden in 1902. 



37. MYRTILLOCACTUS Console, Boll. R. Ort. Bot. Palermo 1: 8. 1897. 



Large cacti, usually with short trunks and large, much branched tops, the stout, few-ribbed 

 branches nearly erect, all the areoles bearing the same kind of spines; flowers diurnal, very small, 

 several, sometimes as many as 9 at an areole, with very short tubes and widely spreading perianth- 

 segments; ovary bearing a few minute scales with tufts of wool in their axils, spineless; fruit small, 

 globular, edible; seed very small, black, with basal hilum. 



