Dischidia nummularia is one plant that is easily overlooked. First, it is not a very showy vine to start with. Second, it does not produce large, showy or colourful flowers. Finally, it has such small leaves that will not catch one’s attention. One will easily dismiss it as a weed. But this plant is quite prevalent in Singapore’s landscape. One will find it climbing its way around old tree trunks and sometimes, long and massive chains of it can be found dangling from the branches of some wayside trees.
Dischidia species are close relatives of Hoya and both genera belong to the frangipani family, Apocynaceae. Dischidia nummularia is sometimes known as pebble beach and button orchid. The latter name is a misnomer as Dischidia nummularia is not an orchid at all! The first name is quite amusing but it is imaginable that a large mass of this plant will create an visual picture that can be likened to a beach full of pebbles! For those who want to know its Chinese name, is Dischidia nummularia is called “圆叶眼树莲”, which translates into ’round leafed dischidia’.
Dischidia nummularia is an epiphytic vine with small, orbicular to ovate leaves that are arranged oppositely along a thin stem. Viewed from the side, the tiny leaves look like little convex lenses! As the plant climbs its way around a tree trunk, it will form roots at the nodes where they will help the vine to cling onto the bark for support and for absorption of water and nutrients. When the plant is injured, it exudes a white latex from the wound.
With everything so small, it is easily envisaged that the flowers borne by Dischidia nummularia would be very tiny too. Indeed, the flowers are quite difficult to spot. They are white in colour and are produced in a cluster. Each flower only measures about 3 to 5 mm across.
Interestingly, it has medicinal uses. Stated in PROSEA, the latex of Dischidia nummularia is applied as an anodyne to wounds caused by fish spines and the decoction of its leaves is drunk to treat gonorrhoea in the Moluccas. In Java, the latex exuded by the plant is used to treat sprue in children. In Thailand, the plant is used against cirrhosis!
This plant is native to Singapore but can also be found growing in Eastern India, Myanmar, Indochina, Thailand, throughout Malesia and all the way to northern Australia. This plant may sometimes piggyback itself on orchid plants and various other plants that are grown epiphytically. Occasionally, one will find this plant on sale in nurseries. It may be sold as a small plant wrapped around a piece of driftwood or grown dangling from a snail shell.
It is not exactly a fast grower and hence do not worry that it will take over your balcony. Dischidia nummularia likes to be grown somewhere where it can get bright light. Six hours of filtered sunshine on a bright balcony or window ledge will be beneficial. It also loves high humidity. This vine should be grown in a porous but moisture-retentive growing mix. Roots should be dry out a little before the next watering.