Adenia stylosa (Adenia stylosa)
Adenia stylosa is reported to be a caudiciform shrub or vine with annual trailing or climbing shoots.
Overview
Adenia stylosa is reported to be a caudiciform shrub or vine with annual trailing or climbing shoots.
Origin and habitat
Adenia stylosa is endemic to Madagascar and is recorded mainly in the north, including Ankarana National Park, Montagne des Français, and Orangea/Rigny. It inhabits shaded places in dry forest and scrub, often on limestone terrain, in rock crevices, and on rock faces, including tsingy limestone environments. It is reported to be native to dry environments in northern Madagascar and, in cultivation, to require warm, frost-free conditions and to be prone to rot in cool, wet conditions.
Characteristics
Few sources report a mature height of about 0–200 cm, and growth is reported to be very slow. The leaves are reported to be heart-shaped to bell-shaped and may be divided or undivided; new leaves may range from violet to dark green with dark red veins, while the Ankarana form commonly has dark red to black leaves and more northerly populations may have glossy red young leaves that mature to dark green. The plant has small pale yellow to greenish-white flowers and is dioecious, with flowering reported from spring to summer. It has a swollen stem, and its tuberous trunk and annual vine-like shoots are reported to become large.
Light
Sources describe this differently: cultivation information for Adenia stylosa recommends bright conditions to light shade, with the tuber shaded, the leaves receiving some sun, and strong direct summer exposure avoided, while genus-level information says Adenia needs full sun.
Watering
During active growth it can be watered more frequently, while in leaf it is generally reported to be kept evenly moist. After the vine-like shoots die back in winter, keep it dry and withhold water while leafless; overly wet growing medium can promote rot, particularly during leafless dormancy.
Temperature and dormancy
Sources differ on the minimum temperature, with the limited information suggesting about 10 °C, while another limited report gives about 15 °C as the cold minimum. Adenia stylosa is frost tender and should be kept above freezing; it is also reported to drop its leaves and go dormant, with dormancy triggered by cold. It is reported to have a USDA hardiness-zone classification.
Growing medium and mounting
Use a very porous, well-drained growing medium that may include pumice, volcanic rock, and perlite; it prefers an acidic medium. It is generally reported to need a very fast-draining mix.
Feeding
During growth, a balanced slow-release fertilizer is reported to be suitable in moderation.
Propagation
Adenia stylosa can be propagated by seed or cuttings; seed propagation is more suitable for developing plants with an ornamental tuberous form, while plants from cuttings flower more readily, although genus-level information indicates that cuttings may not readily form a tuber. The reported propagation methods are seed and cuttings.
Common problems
Overwatering is reported to make the plant prone to rot, with greater risk when it is leafless or dormant in winter, and rot is especially associated with overly wet growing medium. It is reported to be frost tender and to require warmth in winter, with a particular susceptibility to rot under cold, wet conditions.
Identification
The mature storage stem is usually nearly spherical to bottle-shaped, hard, irregular, and deeply wrinkled, with mature skin ranging from gray to beige; the above-ground caudex can become broad and the seasonal climbing shoots long.