CEREUS. 19 



on the upper side of the tubercle, black-felted; spines i to 5, acicular, about i cm. long, brownish; 

 flowering areoles without wool; flowers small, less than 4 cm. long, greenish brown, night-blooming; 

 inner perianth-segments rose-colored; fruit small, spineless. 



Type locality: Mexico, on red lava beds. 



Distribution: Central Mexico. 



This species is reported by Dr. Purpus from near Tehttacan, Mexico, while Dr. Rose 

 collected it at Iguala Canyon, Guerrero, Mexico, in 1905. This latter specimen is now 

 growing in the New York Botanical Garden, but has never flowered. It is not a true Ccrcus 

 nor is it referable to any genus which we know. It is characterized by its peculiar tuber- 

 culate ribs and small flowers. It was named for A. Benecke, a dealer in succulents, at 

 Birkenwerder near Berlin. Echinocactus farinosns (Forster, Handb. Cact. 396. 1846) is 

 a synonym. 



Illustration: Schumann, Gesamtb. Kakteen f. 22. 



CEREUS GRACIUS Haworth, Phil. Mag. i: 126. 1827. Not Miller, 1768. 



Slender, green, nearly erect, terete, simple or with few branches; spines white, at first 2 to several 

 but in age solitary, long; flowers and fruit unknown. 



Type locality: "In America calidiore." 



According to Haworth this species has the habit of Euphorbia hystrix but is less spiny 

 and the spines are half as long. According to Haworth and De Candolle, this species is 

 related to Cereus nanus (Opuntia pestifer}, but a careful study of the descriptions does not 

 suggest a very close relationship. 



CEREUS TENUIS Pfeiffer, Allg. Gartenz. 8: 407. 1840. 



Described as erect, slender, green, shining, with 8 angles; intervals between the ribs acute, 

 narrow; areoles close together, small, bearing white felt, white wool, and straight, acicular yellow 

 spines; radial spines 8, the central solitary; flowers and origin unknown. 



Ccrcus subintortits, C. subintortiis flavispinus Salm-Dyck, and C. liaagcanus Salm- 

 Dyck (Forster, Handb. Cact. 381. 1846) are, according to Forster, of this relationship. 

 CEREUS TRIGONODENDRON Schumann, Bot. Jahrb. Engler 40:413. 1908. 



Tall, 15 meters high, with simple or few-branched stems; ribs 3, prominent; radial spines 6; 

 central spine i, about 6 mm. long; flowers described as about 10 cm. long and red. 



This species was very briefly described by Schumann. Vaupel (Monatsschr. Kak- 

 teenk. 23: 184. 1913) has described the species at more length but not in sufficient detail 

 to enable us to place it. It is very tall with few strict branches and only 3-angled stems, 

 and with red flowers. It probably is not a Ccrcus nor is it like any other Peruvian cacti. 



Type locality: Department of Loreto, Peru. 



Distribution: Northeastern Peru. 



E. C. Erdis, in 1915, collected at Pumachaca, at an altitude of about 1,500 meters, 

 a very peculiar cactus which may be referable here. The small plant which he sent in 

 had only 4 thin wing-like ribs, but the newer growth has 5 ribs; the spines are 6 to 9, 

 dark brown, acicular. A small live plant is in the collection at Washington. 



Illustration: Bot. Jahrb. Engler 40: pi. 10. 



CEREUS MULTANGULARIS (Willdenow) Haworth, Suppl. PI. Succ. 75. 1819. 



Cactus multangularis Willdenow, Enum. PI. Suppl. 33. 1813. 

 ICereus multangularis pallidior Pfeiffer, Enum. Cact. 78. 1837. 

 Echinocereus mnltangularis Riimpler in Forster, Handb. Cact. ed. 2. 825. 1885. 

 Echinocereus multangularis pallidior Riimpler in Forster, Handb. Cact. ed. 2. 825. 1885. 



Cactus multangularis, when first described, was not sufficiently characterized for iden- 

 tification. Schumann associated the name multangularis \rit1i a Peruvian plant and referred 

 considerable synonymy to it. We know no plant of Peru which answers his description. 



