CCREUS. 



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Key to Genera — continued. 



AA. Flowers 2 to several at an arcolc; columnar cacti, or with columnar branches; 



flowers small. 



Flowers without wool; areolcs small. 



Flowering areolcs bearing many long bristles 36, Lophocerrus (p. 177) 



Flowering areoles without bristles 37. Myrtillocactiis (p. 178) 



Flowers densely woolly; flowering areolcs enormously developed. , . •. . .38. Neoraimondia (p. 181) 



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1. CEREUS (Hermann) Miller,* Card. Diet. Abridg. ed. 4. 1754 



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Piptantlwcercus Riccobouo, Boll. R. Ort. Bot. Palermo 8: 225. 1909. 



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Stems mostly upright and tall, but sometimes low and spreading or even prostrate, generally 

 much branched, the branches strongly angled or ribbed; areoles spiny, more or less short-woolly but 

 never producing long silky hairs; flowers nocturnal, elongated, funnelform, the upper part, except 

 the style, falling away from the ovary by abscission soon after an thesis; tube of flower cylindric, 

 expanding above into the swollen throat, nearly naked without; outer perianth-segments obtuse, 

 thick, green or dull colored, the inner thin, petaloid, so far as known white, except in one species 

 and in that red; stamens numerous, varying greatly in length, slender and weak, included; style 

 slender, elongated but often included; stigma-lobes linear; ovary bearing a few scales naked in their 

 \ axils; fruit fleshy, red, rarely yellow, naked, splitting down one side when mature, often edible; 

 seeds black. 



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Type species: Cactus hexagonus Linnaeus, this being the first species cited by Miller 

 in his Gardeners' Dictionary, 8th edition, 1768, where he described 12 species of Ccrcus (in 

 the 4th edition, abridged, 1754, he described 14 species), which we now ^now belong to 

 several genera. . . 



The genus Cereus has been understood by authors at one time or another since Philip 

 Miller*s time as containing species of nearly all the genera of cacti, including even Rhipsalis 

 and Opuntia, Schumann, in his monograph, recognized 104 species, to which he afterward 

 added 36 in his supplement. His treatment of the genus is artificial and complex; Berger's 

 treatment (Rep. Mo. Bot. Gard. 16:57 ^^ 86. 1905) is much more natural but more 

 inclusive, for he added EchinopsiSy Pilocercus, Cephalocereus., and Echinoccrcus, and even 

 suggested the possible transfer here of Pkyllocactus; he divided the genus into 18 subgenera, 

 most of which we believe require generic recognition (Contr. U. S. Nat. Herb. 12:413 to 

 437. 1909), as also indicated by Riccobono (Boll. R. Ort. Bot, Palermo 8: 215 to 266. 

 1909). From some of Berger's conclusions we differ, but chiefly in cases where he knew 

 the plants only from herbarium specimens or from literature. In his treatment of Cereus 

 Berger referred the species which we include in it to his series Piptanthocereus, while he 

 took up for the Eucereus a different series, but he indicated no type species. Our treat- 

 ment includes all the species of Schumann's series Compresso-costati, Formosi, and Coeru- 

 lescentes, and the two species, C. ietragonus and C. hankeanus of Oligogoni. It corresponds 

 to Berger's subgenus Piptanthocereus, but is not so inclusive. We recognize 24 species, 

 which have similar flowers, fruit, spines, and branches; these extend, from the southern 

 West Indies through eastern South America to Argentina. The fruits of several species 



are edible. 



./^ The number of published Cereus binomials involved is about 900, exceeded in this 

 family only by Mammillaria and perhaps by Opuntia. 



The name Cereus is from the Greek, also from the Latin, signifying- a torch, with reference 

 to the candelabrum-like branching of the first species known. It was used by Tabernaemon- 

 tanus on page 386 of the second part of his Kreuterbuch, published in 1625, a plant called 



Cereus peruvianus being there illustrated; this figure represents a tall, columnar, branching 

 species, perhaps the same as the one to which the name peruvianus has been applied by 



odern authors. 



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*PhiHp Miller credits the genus Cereus to P. Hermann (Par. Botavus 112. 1698) although the name Ccrcus had 

 then been in use more than seventy years. 



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