30 



THE CACTACEAE. 



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Type locality: Guadalajara, Mexico. 



Distribution: In hedges about Guadalajara, Mexico. 



The fruit, called in Mexico tuna de agua and tasajillo, is used m ma 



drink and for preserves. 



Opuntia spathulaia aquosa (Bull. Mus. Hist 



synonym of this species, but was 



1898) was given as a 



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Rep. Smiths 



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Figure 27 repres' 

 Guadalajara^ Mexico 



plant collected by W. E. Safford near 



*^ 



Pereskiopsis kellermanii Rose, Smiths. Misc 



1907. 



Stem glabrous, herbaceous, weak, and clambering over shrubs to a length of 4 to 5 meters, 

 about 2 cm. in diameter; second-year branches usually at right angles to main stem, with cherry- 

 red bark; old stem bearing several slender, acicular brown spines, sometimes only i, sometimes 

 wanting, and numerous brown glochids; young branches green, fleshy, their areoles circular, white, 

 filled with long white hairs, brown glochids, and often with several 

 acicular brown spines; spines on wild plants often stout, usually 

 solitary, nearly black, 2 to 3 cm. long; leaves various, shining green, 

 glabrous, thickish, elliptic and two or three times as long as wide, 

 or suborbicular, acute at the apex, narrowed at the base, 5 cm. long 

 or less, 2 to 2.5 cm. broad; flowers not known; fruit red, glabrous, 

 leafy, 3 to 6 cm. long, bearing large areoles filled with brown 

 glochids; seeds covered with matted hairs. 



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Type locality: Trapichite, Guatemala. 

 Distribution: Guatemala. ' 



Figs 28, 29, and 30. — Pereskiopsis keller- 

 manii. showing three leaf forms. X0.5. 



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Figures 28, 29, and 30 are copied from sketches of the leaf-forms of the type plant, 

 made by W. A. Kellerman in Guatemala in 1908. 





2. PTEROCACTUS Schumann, Monatsschr. Kakteenk. 7: 6. 1897. 



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Stems low, more or less branched above, cylindric, from tuber-like and often greatly enlarged 

 roots; leaves minute, caducous; spines weak, several or many at each areole; glochids small, cadu- 

 cous as in Opuntia; flower terminal, regular, without tube; perianth-segments several, erect; fila- 

 ments and pistil shorter than the petals; ovary nearly turgid, bearing numerous small clusters of 

 spines; fruit dry, capsular, dehiscent; seeds winged, white; embryo curved- 



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Type species : Pterocactus kuntzei Schumann. 



Four species have already been described, but three of these we have combined and 

 the fourth is referred to Opuntia. Three additional species, however, are here described. 

 The generic name refers to the winged seeds. 



This is a remarkable genus, and it is surprising that it remained unrecognized so long. 







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known 



Opuntia, having large roots and short, weak stems 



however, seem noi 

 some of the anom 



Opuntia chaffeyi 



Mexico; the seeds, however, differ, not only from those of Opuntia, but from 



all other cactus genera, in being winged. The 

 we have not been able to confirm his observation 



Schumann 



lum. 



Another peculiarity is that the fruit is borne in the end of the stem or branch. 

 While this genus has good characters, it is no more distinct than many others and does 



importance given to it by T. von Post and Otto Kuntze in Lexicon 





Generum Phanerogamarum 

 conserved, in their view. 



it as one of the only three cactus genera to be 



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