Hibiscus columnaris (Mahot Rempart) is endemic to Mauritius and Réunion Islands, however, on Mauritius it is considered extinct since the last specimen was seen in the 19th century. On Réunion, there are only a few remaining specimens. This small, often multi-trunked tree grows up to 2m tall, in semi-dry regions of the island. It is a good candidate for a water conserving garden. The flowers are yellow, and leaves are slightly fuzzy giving them a sandpaper-like feel. The leaf shape is similar to that of Hibiscus mutabilis, however, the flowers are quite different.This hibiscus is a small tree up to ten meters high with a trunk diameter of 30cm.
Hibiscus columnaris is often much branched at its base. Bark of Hibiscus columnaris is smooth and still green even on the mature trunk. The early leaves are sometimes palmate becoming tricuspid when mature. Their shape evokes that of some Dombeya. In Hibiscus columnaris the stipules are long, clearly visible at the base of the stalk. Usually flowers appear from April to July at the base of leaves and have yellow color petals that continue parallel to the imposing stamenal column, characteristic of Hibiscus. Flowers are protruding and artistic but rarely fruit and seed. It has become exceptional and is no longer found in the semi-dry forests of the low and medium altitudes.