STANDLEY TREES AND SHRUBS OF MEXICO. 901 



fornia. This fruit is round, of the size of a large peach, and is also armed 

 with spines; at first it is green, but when ripe it turns red or yellow. That 

 with red rind has pulp of a beautiful blood-red color, and that with yellow 

 rind has white or yellow pulp. The rind is rather thick but soft and easily 

 separated, and the pulp is sweet, mild, refrigerant, and wholesome. After 

 the rind is removed the pulp is eaten, along with the seeds, with which it is 

 filled, which are somewhat like those of the fig, although smaller. The red 

 pitahayas color the urine like blood, for which reason some strangers who 

 have eaten them have been much alarmed, thinking that they have broken 

 a blood vessel. In the southern part of the peninsula the harvest of the sweet 

 pitahayas begins the first of June, and ends the last of August ; in the northern 

 part it begins later and is most abundant in August; but when there is a 

 little more rain than usual the harvest is very scant or none at all, for there 

 is no plant so much injured by dampness as the pitahayo. For harvesting, 

 the Californians use a stick to one end of which is firmly attached a slender 

 hook-sliaped bone, for pulling off the fruit, and a net in which to catch it 

 without letting it fall on the ground. After it is gathered, they take off the 

 spines with a little stick, which is easily done if the fruit is ripe, and then they 

 peel and eat it; and in this way they go about gathering and eating until 

 filled, and what is left they take home. During the time of the harvest the 

 people go all day long over the mountains and plains hunting for ripe pitahayas, 

 and for them, as we shall see later, this is the happiest season of the year." 



11. Lemaireocereus dumortieri (Scheidw.) Britt. & Rose, Contr. U. S. Nat. 

 Herb. 12: 425. 1909. 



Cereus dumortieri Scheidw. Hort. Belg. 4: 220. 1837. 



Morelos and Hidalgo and elsewhere in central Mexico. 



Often treelike, 6 to 15 meters high, the trunk proper short, 60 to 100 cm. 

 long, 30 cm. in diameter or more, woody ; branches many, erect almost from 

 the first, with numerous constrictions, very pale bluish green or somewhat 

 glaucous ; ribs generally 6, sometimes 5 or 7, occasionally 9 on very old joints ; 

 areoles elliptic, approximate or often confluent, gray-felted ; spines various in 

 number and in length, 10 to 20 radials, 1 central or more, the longer ones often 

 4 cm. long, all at first straw-colored but in age blackened ; flowers 5 cm. long, 

 the tube and ovary bearing small ovate scales with bunches of felt and occa- 

 sionally bristles in their axils, the limb about 2.5 cm. broad ; fruit oblong, 3 

 to 4 cm. long, reddish within, not spiny, its areoles nearly contiguous, felted ; 

 seeds brownish, 1.5 mm. long, dull, roughened. 



Cereus anisacanthus DC. (Mgm. Mus. Hist. Nat. 17: 116. 1S2S) is doubtfully 

 referred here by Schumann. 



DOUBTFUL SPECIES. 



Cereus conformis Salm-Dyck, Cact. Hort. Dyck. 1849. 203. 1850. Type from 

 Mexico. 



Cereus kigidispinus Monville, Hort. Univ. 1: 223. 1840. Type from Mexico. 

 Both this and the preceding probably represent species of Lemaireocereus. 



10. BERGEROCACTUS Britt. & Rose, Contr. U. S. Nat. Herb. 12: 435. 1909. 



The genus consists of a single species. 

 1. Bergerocactus emoryi (Engelm.) Britt. & Rose, Contr. U. S. Nat. Herb. 12: 

 435. 1909. 



Cereus emoryi Engelm. Amer. Journ. Sci. II. 14: 338. 1852. 



Northern Baja California and on the adjacent islands. California. 



Branches 20 to 60 cm. long, 3 to 6 cm. in diameter, entirely covered with 

 the dense spiny armament ; ribs 20 to 25, very low, only a few millimeters high, 



