PERESKIA. 9 



Type species: Cactus pereskia Linnaeus. 



In 1898 about 25 names had been proposed in Pereskia, but, in his monograph pubHshed 

 that year, Karl Schumann accepted only 1 1 species. Several new ones have been proposed 

 since the publication of Schumann's monograph. 



The species are., native in Mexico, the West Indies, Central America, and South 

 America. Soine of the species are much used as stocks for growing the various forms of 

 Zygocactus, Epiphyllmn, and other cacti requiring this treatment; P. pereskia is most 

 used and P. grandijolia next. Several species are widely cultivated as ornamentals in 

 tropical regions; they do not flower freely under glass in northern latitudes. All species 

 studied by us in the living state grow readily from cuttings. 



The typical species seems to have been first introduced into Europe from the West 

 Indies in the latter part of the sixteenth century. A straight-spined species was first 

 described and figured by L. Plukenet in 1696, who called it a portulaca, and the next year 

 by Commerson as an apple {Malus). In 1703 C. Plumier described the genus Pereskia, 

 basing it upon a single species. The genus was repeatedly recognized by Linnaeus in his 

 earlier publications, and by some pre-Linnaean botanists, but in 1753 Linnaeus merged it 

 into Cactus along with a number of other old and well-established genera; but it was 

 retained by Phihp Miller in 1754 in the fourth edition (abridged) of his Gardeners' Dic- 

 tionary and has since been generally recognized as a genus by botanical and horticultural 

 authors. 



The name is variously spelled Peirescia, Peireskia, Perescia, and Pereskia. 



Named for Nicolas Claude Fabry de Peiresc (1580-1637). 



Key to Species. 



Climbing vines, the twigs with a short pair of reflexed spines from each areole, the stem with 



acicular spines (Series i. Typicae) 1. P. pereskia 



Shrub or trees with slender straight spines (Series 2. Grandifoliae). 

 Petals toothed or fimbriate. 



Petals somewhat toothed 2. P. aidumnalis 



Petals fimbriate. 



Species from Mexico; ovary turbinate 3. P. lychnidiflora 



Species from Costa Rica; ovary pyriform 4- -P- nicoyana 



Petals entire, at least not fimbriate. 



Branches and leaves very easily detached 5. P, zehntneri 



Branches and leaves not easily detached. 



Axils of sepals bearing long hairs and bristles. 



Leaves lanceolate 6. P. sacharosa 



Leaves orbicular 7. P. moorel 



Axils of sepals not bearing long hairs and bristles. 



Flowers white 8. P. weheriana 



Flowers not white. 

 Petals yellow. 



Leaves Ian eolate to oblong or obovate 9. P. gtiamacho 



Leaves orbicular or broadly ovate 10. P. colombiana 



Petals red or purple. 



Spines few or none 11. P. tampicana 



Very spiny, at least on old branches. 

 Flowers terminal. 

 Flowers panicled. 



Fruit naked, broadly truncate 12. P. bleo 



Fruit leaf -bearing, not truncate. 



Leaves of ovary cuneate at base 13. P. bahiensis 



Leaves of ovary broad at base 14. P. grandifolia 



Flowers solitary 15. P. zinniaeflora 



Flowers usually axillary and solitary. 



Leaves i cm. long or longer, obtuse or acute. 



Flowers 2 to 5 together, i cm. long; South American species. ... 16. P. horrida 

 Flowers solitary, 1.5 cm. long; petals elliptic-obovate; Cuban 



species 17. P. cubensis 



Leaves emarginate, i cm. long or less, petals obovate 18. P. port-, 



Affinity unknown 19. P. conzattii 



