CEREUS. 17 



This species is similar to the so-called Cereus coerulescens, of Argentina, which was 

 taken up as Cereus landbeckii by Philippi, but the former has different stems, is stouter, and 

 usually has shorter spines. 



Cereus chalybacus was described from a plant grown in the Botanical Garden at Berlin 

 in 1846, which we do not know; but we are accepting as this species the plant so identified 

 and figured by T. Giirke as below cited. Our description of the flower is drawn from 

 this illustration. 



Dr. Schumann states that the species comes from near Cordoba, Argentina, and there 

 Dr. Rose collected specimens in 1915 which have been used for this description. 



Walpers (Repert. Bot. 2:340. 1843) referred this species to C. polychaetus, an older 

 species which seems to have been overlooked by recent writers. 



Illustrations: Bliihende Kakteen 3: pi. 135; Schumann, Gesamtb. Kakteen f. 27. 



21. Cereus aethiops Haworth, Phil. Mag. 7: 109. 1830. 



Cereus coerulescens Salm-Dyck, Hort. Dyck. 335. 1834. 



Cereus landbeckii Philippi in Regel, Gartenflora 24: 162. 1875. 



Cereus coerulescens landbeckii Schumann, Gesamtb. Kakteen 122. 1897. 



Cereus coerulescens melanacanthus Schumann, Gesamtb. Kakteen 122. 1897. 



Stems bluish green to purplish, i to 2 meters high, usually much branched; joints 3 dm. long or 

 more, somewhat tapering toward the apex ; ribs 7 or 8, low, somewhat tuberculate, obtuse or rounded, 

 separated by acute intervals; areoles large, black; radial spines about 9 or even more, black, at least 

 at bases and tips; central spines usually solitary, a little stouter than the radials, ascending; flower 

 long, tubular, 22 cm. long, with a limb 12 cm. in diameter; outer perianth-segments linear-lanceolate, 

 rose-colored; inner perianth-segments white; filaments and style included, the former attached all 

 along the inner surface of the long tube; fruit ovoid to oblong-ovoid, more or less brownish when 

 mature, truncate at apex, with a thick rind, smooth, somewhat glaucous, 6 cm. long; seeds black, 

 2 mm. long, coarsely tuberculate above, finely tuberculate at base, with a large depressed hilum. 



Type locality: Brazil. 



Distribution: Western border of Argentina to Brazil. 



Cereus niendory Hortus (Pfeiffer, Enum. Cact. 85. 1837), C. melanacanthus Hortus 

 (vSchumann, Gesamtb. Kakteen 122. 1897), and C. nigrispinus Labouret (Schumann, 

 Gesamtb. Kakteen 122. 1897), usually cited as synonyms of this species, are unpublished. 

 Cereus coerulescens julmspiniis (Graebener, Monatsschr. Kakteenk. 19: 137. 1909) and 

 C. coerulescens longispinus (Weingart, Monatsschr. Kakteenk. 16:93. 1906) are referred 

 here, but they have not been described. 



Cereus cocruleus Lemaire (Cact. Gen. Nov. Sp. 80. 1839) was supposed to be a variety 

 of the above species when first described but was said to be twice as large with stouter, 

 longer spines. 



We have followed Schumann and others in combining the plants from Brazil and 

 western Argentina under one name, although there are indications that the specimens from 

 Mendoza, Argentina, which were taken up by Philippi as C. landbeckii, are distinct. 



Illustrations: Curtis's Bot. Mag. 68: pi. 3922; Pfeiffer, Abbild. Beschr. Cact. 2: pi. 24; 

 Schumann, Gesamtb. Kakteen f. 28, all three as Cereus coerulescens; Gartenflora 24: pi. 

 832, as Cereus landbeckii; Bliihende Kakteen 3: pi. 127, as Cereus coerulescens melana- 

 canthus. 



Figure 16 is from a photograph taken at Alto Pencoso, San Luis, Argentina, by C. 

 Bruch in 1914; figure 17 shows a fruiting branch of C. aethiops from Mendoza, Argentina, 

 brought by Dr. Rose to the New York Botanical Garden in 1915. 



22. Cereus repandus (Linnaeus) Miller, Gard. Diet. ed. 8. No. 5. 1768. 



Cactus repandus Linnaeus, Sp. PI. 467. 1753. 



Cereus hermannianus Suringar, Versl. Med. Akad. Wetensch. III. 2: 194. 1886. 



Pilocereus repandus Schumann in Engler and Prantl, Pflanzenfam. 3 6a : 181. 1894, as to name. 



Tall, tree-like plant, up to 10 meters high, with a much branched top; trunk 4 dm. in diameter; 

 branches grayish green, usually upright or somewhat curved below, bearing numerous constrictions 



