PERESKIA differs from the rest in having woody stems and leaf-bearing branches, the leaves being somewhat fleshy, but otherwise of the ordinary laminate character. One species, the Barbadoes gooseberry, climbs like the blackberry (Rubes) by recurved thorns; the others are spiny shrubs. The flowers are subpaniculate, white or yellowish. They are frequently used as a stock on which to graft other Cacti. There are about 19 species, mainly Mexican; P. cubensis is a peculiar little tree of eastern Cuba.