Uncarina is a genus of plant in family Pedaliaceae. Originating in Madagascar, the deciduous shrub may sometimes be considered a small tree as it grows to 25 feet (7.6 m) tall. Leaves are oval and green and flowers bell-shaped and tubular. Uncarina blooms easily, and when covered with flowers, it is a striking vision. The seed capsules feature small hooked harpoons.
There are about 15 species and all species are in cultivation. There are three flower colours to be found: red, white and yellow. The latter is the most common. Only one species has a true caudex, Uncarina roeoesliana. It is also the easiest one to flower; it can already flowers when still small. The rarest is Uncarina leptocarpa, the only white-flowering species.
Light: This heat resistant plant does best when grown in part shade to full sun.
Temperature: Uncarinas are tender, cannot endure temperatures below 35 2° F (2° C), if grown outdoors they will probably grow back from roots, if frozen. They are quite heat tolerant.
Water: Water abundantly when actively growing and keep dry when dormant.
Soil: Uncarina needs a rich, very well drained potting soil.
Fertilizer: Use diluted fertilizer on young plants to speed up growth.
One reason that Uncarinas are not common in cultivation is that the seed does not germinate easily. Why this is, we do not know. Propagation by cuttings is not a substitute because they do not root easily either. In short: a difficult sort to propagate.
But, once you have managed to get yourself one, it is relatively easy to grow. It needs plenty of warmth and plenty of water in the growing season, but keep it dry in the winter. In the wild they can grow up to 13 feet (4 m), but do not expect that in your greenhouse or window sill.