i68 



CACTACKAI'. 



central and longer ones sometimes 3 cm. Ion;;, those- on old and flowering branches numerous, when 

 \oiui- biownish, in age nearly white, all weak, bristle-like, 3 to 8 cm. long, hardly pungent; flowers 

 I in s fin. long, white-; scalr> on ovarv and tube minute, numerous, bearing tufts of white wool in 

 their axils; immature fruit sometimes longer than broad; mature fruit either globular or a little dc- 

 pn-sstd. red, said to be edible, bearing scattered minute areoles with small tufts of wool; pulp white; 

 seeds numerous, black. 



7'r/v /i)iu/;/r: Near Chosica, Peru, at 800 meters altitude. 



Distribution: Mountains of western Peru. 



The top of the flowering plant is made up of a compact mass of long white or yellowish 

 bristle-like spines from one side of which the flowers appear, and this F. Vaupel has termed 

 a lateral cephalium. 



Plate xxiv, figure 3, shows the top of a sterile plant brought by Dr. Rose from the type 

 locality in 1914. Figure 236 is from a photograph taken by Dr. Rose at Santa Clara, Peru, 

 in 1914; figure 238 shows the fruit of the plant photographed at Santa Clara. 



FIG. 238. Fruit of B. 

 melanostele. Xo.6. 



FIG. 239. Flower of Binghamia 

 acrantha. Xo..7. 



Fie,. J4o. Fruit of Binghamia 

 acrantha. Xo.7. 



2. Binghamia acrantha (Vaupel). 



Cereiis acranthus Vaupel, Bot. Jahrb. Engler 50: Beibl. in: 14. 1913. 



Stems i to 3 meters high, much branched at base, the branches usually erect, 5 to 8 cm. thick; 

 ribs 12 to 14, low, somewhat tuberculate above, but on older parts with mere constrictions; areoles 

 large, approximate, felted and spiny; felt at first yellow, then brown, finally black; spines at first 

 yellow, numerous, short, and spreading, except the i or 2 centrals, which are stouter, 3 to 4 cm. long, 

 porrect or reflexed; flowers opening in the early evening; flower 6 to 7 cm. long, gradually tapering 

 upward from base, about 2.5 cm. in diameter at the top; scales on ovary and flower-tube small, 

 acute, with small tufts of wool in their axils; upper scales and outer perianth-segments mauve; 

 limb 4 to 5 cm. broad when fully expanded; inner perianth-segments usually white, sometimes 

 greenish, oblong, obtuse, 2 to 2.5 cm. long; style cream-colored, much exserted; stigma-lobes greenish; 

 fruit red, its pulp white, edible, slightly acid. 



Y'v/v locality: Santa Clara, east of Lima, Peru. 



Distribution: Very common on the hills above Lima, from Santa Clara to Matucana. 



This is one of the most common species in central Peru, being especially abundant on 

 the hillsides and in the narrow valleys between the hills, but not extending down into the 

 broad valleys. It often forms dense thickets. In the lower parts of its range, where the 

 fogs are abundant, especially about Santa Clara, the branches are often covered with 

 lichens and tillandsias. 



Our specimens of flowers were obtained by bringing in fully developed buds and allow- 

 ing them to open ; these began to open about 6 o'clock in the evening and were fully 

 expanded at 9. 



