14 



THE CACTACEAE. 



5. Pereskia (?) zehntneri sp. nov. 



Shrub, 2 to 3 meters high, with a central erect trunk, very spiny; branches numerous, horizontal, 

 usually in whorls, sometimes as many as lo in a whorl; branches terete, green, fleshy, very easily 

 detached from the stem; leaves stiff, fleshy, numerous, small, 2 to 4 cm. long, ovate to orbicular, 

 acute, standing at right angles to the branches; areoles large, filled with short white wool and 

 numerous slender white spines ; flowers at tops of branches, large, 7 to 8 cm. broad, bright red, appear- 

 ing in November; petals broad, retuse; ovary borne in the upper end of the branch, very narrow, 

 3 to 4 cm. long, bearing the usual leaves, areoles, and spines of the branches. 



Collected by Dr. Leo Zehntner (Nos. 567 and 

 630, type) November 15 and 16, 1912, at Bom Jesus 

 da Lapa, Bahia, Brazil, on the Rio Sao Francisco. 



This is a very rare plant and seen in only one 

 locality, in soil of a pecuhar chalky formation. Liv- 

 ing plants were taken by Dr. Zehntner to the Horto 

 Florestal, Joazeiro, Brazil, where they grew well, and 

 whence Dr. Rose obtained specimens in 1915 which 

 were shipped to the United States under No. 19722. 



The plant is known in Bahia under the name 

 quiabento. It is probably not a true Pereskia; it sug- 

 gests in its habit and foliage some of the Mexican spe- 

 cies of Pcreskiopsis, but it may represent a distinct 

 genus. 



Text-figures 6 and 7 are from the type plant 

 above cited. 



6. Pereskia sacharosa Grisebach, Abh. Ges. Wiss. Gottin- 



gen 24: 141. 1879. 



Pereskia amapola Weber, Diet. Hort. Bois 938. 189S. 

 Pereskia argeniina Weber, Diet. Hort. Bois 938. 1898. 



Small tree or shrub, 6 to 8 meters high ; branches green 

 and smooth, but in age becoming yellowish or light brown ; 

 leaves lanceolate to oblanceolate, 8 to 12 cm. long, cuneate 

 at base, more or less pointed at apex; j^oung areole with i to 

 3 spines, the longest 5 cm. long, the others when present 

 not over half as long, all acicular and dark in age; older 

 areoles often with 6 or more spines; pedicels sometimes 10 

 mm. long; flowers in terminal clusters, either white or 

 rose-colored and very showy, 8 cm. broad, open at midday; sepals about 8, i or 2 petal- like, the others 

 scale-like, the outer sepals and upper scales bearing long hairs; petals 8, rose-colored, oblanceolate, 

 3 cm. long; stamens free from the petals, numerous, unequal, erect; filaments, style, and stigma- 

 lobes white ; o\'nles borne on the lower part of ovary ; ovary bearing small leaves, their axils filled with 

 short wool and occasionally bearing a spine ; fruit hard, 2.5 to 4 cm. in diameter, more or less tapering 

 at base, many-seeded, leafless or nearly so, sometimes proliferous. 



Type locality: Cobos, Oran, Argentina. 



Distribution: Paraguay and Argentina. 



Schumann (Gesamtb. Kakteen 765. 1898) gives Opitntia sacharosa Grisebach as a 

 synonym of this species, but erroneously, since it w^as never taken up by Grisebach as an 

 Opuntia. The Index Kewensis refers this species to P. aculeata, doubtless following 

 Hooker's references in Curtis's Botanical Magazine for 1890 in regard to Argentine plants, 

 which even then were little known. 



The common name of this plant in Argentina is sacharosa. It is sometimes used as 

 a hedge plant. 



Plate II, figure 4, represents a leafy branch of a plant given to the New York 

 Botanical Garden by Frank Weinberg in 1903; figure 5 shows its fruit. 



-Pereskia zehntneri. Photograph 

 by Paul G. Russell. 



