Uncarina grandidieri is a multibranched shrub or small pachycaulescent tree that may ultimately attain a height of 3-5 meters and 80 cm girth. The flower resembles a large Petunia in form and is bright yellow with a dark throat, as in the "Black Eyed Susan Vine" (Thunbergia alata) and give way to green fruit covered in otherworldly spines. The stems are stout and become thickened with age. The leaves resemble those of the cotton plant (genus Gossypium) and are fuzzy and are sticky to the touch, yielding a musty odour when rubbed. The leaves are deciduous during the winter resting season.Derivation of specific name: The species is named in honour of Alfred Grandidier (1836-1921), an intrepid explorer and collector in Madagascar.
It should be watered plentifully in Summer and kept drier in Winter. This species like all Uncarinias, is sensitive to excess moisture, and should be kept on the dry side. It rot easily and do not like any water when it has no leaves.
Due to their Madagascan origin keep warm in winter, the minimum safe average temperature is 10°C, although they can go lower for short periods (cannot endure temperatures below 2° C). If grown outdoors they will probably grow back from roots, if frozen. They are quite heat tolerant, and survive easily temps above 45° in summer, without dropping leaves.
The seed pods are covered with barbed hooks. Don't touch this fruit unless you want to spend some time trying to remove it from your fingers. Remove the pods when they are still green and pliable (if they are dry, use long-handled clippers or hemostats) and dispose of carefully.