This hibiscus relative that I saw recently made the location where it is now growing in Singapore seemed as if it was autumn in the tropics! The deeply lobed, palmate leaves found on the plant are deep red in colour and they looked so similar to the red leaves of Japanese maple trees in the autumn season.
The plant is botanically known as Hibiscus acetosella and is known by various common names such as the False roselle, Red-leaved hibiscus, African rosemallow or Sorrel roselle. Without much doubt, it is a member of the hibiscus family, Malvaceae.
This is the first time I have seen such a magnificient specimen with my very own eyes. I have not seen it being sold commercially in our local nurseries. One other occasion that I have seen it in Singapore was in a community garden’s medicinal plant section.
I am personally very impressed with its deep red leaves and unlike its flowering relatives loved for their blooms, H. acetosella is appreciated for its deep red-purple foliage that is quite rare amongst the many ornamental plants we can find around us. It confers a great contrast with green and silver-leaved plants.
Interestingly, it was stated in PROTA’s (Plant Resources of Tropical Africa) database that H. acetosella is probably an amphidiploid species possibly originating from hybridization between H. asper and H. surattensis. An amphidiploid species is a tetraploid that possesses two sets of genomes coming from different parent stocks. A handful cultivars of the red-leaved form are available but a green-leaved variety is said to be in existence too.
Although the plant I saw and photographed was not in bloom, the flowers of H. acetosella have been described to feature pink or yellow petals with a base that is red-purple or wine-red in colour. Each flower that is produced singly between the leaf axils easily gets hidden away by the leaves of a plant with a dense canopy. Flowers are reported to be self-pollinating. Both the flowers and fruits bear much resemblence as those found on the true roselle, H. sabdariffa.
The flower of H. acetosella (Courtesy of Ms Rosalind Tan).
Hibiscus acetosella grows a rather fast-growing woody shrub and it can be propagated via seeds and stem-cuttings. Plants are best grown under direct sun to ensure the production of stunning red foliage and a compact growth habit. Like most other shrubs, H. acetosella prefers to be grown in well-drained, moist and fertile soil. Several plants can be grouped and grown closely together to obtain a bushier appearance, such as to form a hedge or a small colony. Plants should be periodically pruned and pinched to encourage branching and prevent straggly growth.
The young leaves and shoots of H. acetosella can be consumed as a vegetable. The leaves which remain red even after cooking are mucilaginous and more sour to taste than the true roselle. Hence it is not a leafy vegetable suitable for serving to quite a lot of people. The red flowers can be infused to make a tea, in a similar way with what has been done with the red calyces of the true roselle. The root is edible but insipid and fibrous.
The plant possesses some medicinal properties. In Angola, an infusion of the leaves in water is used as post-fever tonic and is also used to treat anaemia. In East Africa, children with an aching body are washed in cold water to which some mashed H. acetosella leaves have been added.