| Grapes These grapes weren’t made for eating, and not for making into wine, either. Along with more familiar plants, Vitaceae, the grape family, contains a number of spectacular succulent plants. The succulent grapes fall into three general categories: vining plants, clambering plants with thickened, segmented, often angular stems, and caudiciforms, with enormously swollen bases either elongated into trunks or squat as egg-shaped boulders. All the succulent grapes were once included in the genus Cissus, but decades ago the caudiciform types were separated out into Cyphostemma where they remain today. Only a relatively few species of the widely dispersed genus Cissus are succulent plants (many of the other species are tropical vines, often with very decorative leaves), but all cyphostemmas are succulents.
The succulent species left in cissus proper encompass the vining and clambering species, and grow in more-or-less arid regions in both Africa and Mexico . Most of the vining plants are Mexican, with annual, large-leafed vines rising from underground tubers. Cissus tuberosus, from the northwestern Mexican state of Sonora , differs from its relatives because of its deeply dissected leaves, and its above-ground caudex. C. tuberosusis easy to grow but needs a lean soil mix, a winter rest after its leaves fall , and careful watering when growing in order to develop a large caudex.
The clambering cissus species, such as C. quadranglularis, have succulent stems and quickly ephemeral leaves. Though they develop thickened tuberous bases in time, their stems aren’t annual; in habitat they can cover small trees and shrubs. These species live in quite arid regions of East Africa and southern Arabia , and, not surprisingly, do best with very bright light and fairly strict winter dry periods.
Although cyphostemma was separated from cissus because of technical details of flower structure, once seen few cyphostemmas would ever be mistaken for a cissus. Cyphostemmas, strictly African in origin, are prized even as young plants because of their striking caudices often covered with peeling, papery bark. The most common cyphostemma in cultivation is the South African and Namibian C. juttae , that under ideal circumstances can reach over six feet in height and more than two feet in diameter at the base. Often growing with a slight curve, it somewhat resembles a swollen elephant tusk growing out of the ground topped with a few large, tri-lobed, fleshy, green leaves. A second species, C. uter(from the dry plains of northern Namibia ) grows with an arcing, almost crescent-moon-like habit, the ends of the arc being the tips of its short, thickened branches. The largest species, C. currorii, with thick leaves sometimes covered in white felt, can reach twenty feet in height, with a base eight feet in diameter surmounted by a crown of three or four upright, two-foot thick branches. Conversely, the rare C. seitziana, also from Namibia, but from the bleak dry slopes of eight-thousand foot high mountains rather than the flats, forms a perfect egg shaped caudex up to a foot tall, with a couple of short branches that put out two or three lobed leaves (also covered in silvery felt) during its four or five month growing season.
Other cyphostemmas live in the east of South Africa , and occur sporadically up the eastern side of the continent as well, as far north as Somalia , where the extremely rare C. betaeformisexactly resembles the squat, branching Namibian species. Several more species , such as C. elephantopus, grow in Madagascar , and like some of the East African species, these send out fairly long vines from strange, flask-like caudices which can attain surprisingly large dimensions.
The tropical cyphostemmas need much the same care as the east African cissus species; lots of light, protection from cold, reasonable amounts of water when growing and a fairly rigorous dry period when their leaves drop in winter until their new growth starts in spring. C. juttaee, by far the most common cyphostemma in cultivation, requires the same general treatment, but it is surprisingly cold hardy. The C. juttaeon African Hill has survived cold-snaps below twenty degrees Fahrenheit. More unusual species, such as C. curroriiand C. utermust be protected from cold and kept very dry when dormant, while C. seitziana (which should be given less water when growing and a strict winter rest period) often doesn’t leaf out until mid-June and can go dormant as early as October. Even C. juttaeis still a rare plant in cultivation, and the less common cyphostemmas are among the most coveted of collector’s items.
The Garden has several very nice specimens of cyphostemma, and a number of unusual Mexican and African cissus species as well. We occasionally have some succulent cissus for sale; perhaps one of these days we’ll be able to offer some cyphostemmas as well. By the way, the fruit of cyphostemma somewhat resemble grapes, but since they’re filled with oxalic acid, they’re best left alone.
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