An endemic species of orchid, Nervilia singaporensis, was discovered in July last year at Bukit Timah Nature Reserve by researchers from the Singapore Botanic Gardens. The genus Nervilia was, until recently, thought to be locally extinct in Singapore. Thus, Nervilia singaporensis is at present the only species of Nervilia found in Singapore and this plant can only be found in Bukit Timah Nature Reserve. With this discovery, Singapore now has five species of endemic plants, of which four exist only in our nature reserves. These serve as a reminder of the important role our nature reserves play as core biodiversity habitats for native species.
This discovery of Nervilia singaporensis is unique in that the last sighting of a Nervilia in Bukit Timah Nature Reserve was in 1889, when the Singapore Botanic Gardens’ first scientific director Henry Nicholas Ridley collected it. However, Ridley mistakenly identified the species as Nervilia punctata, a species found in Java, Indonesia. Nervilia singaporensis, on the other hand, has a unique flower shape that is oblong with a truncate tip and flowers that never open. As its flowers never open, it must self-pollinate in order to reproduce. Ridley’s error was further confirmed by researchers at the Gardens after they studied the structural features and DNA sequences of the species, as well as comparing with existing Herbarium records.
Characteristics critical for distinguishing Nervilia species are often obscure, which may explain the previous confusion. The genus is poorly collected and understood – its flowers, which are critical for identification, are short-lived, lasting for only a few days. It is also difficult to prepare specimens for herbarium collections as the flower and leaves are present at different times. In Singapore, for instance, there are only a few historic collections of the species, with only one ever bearing flowers.
Nervilia is a genus in the widespread plant family Orchidaceae and can usually be found growing on the forest floor. The genus Nervilia occurs widely in Africa, Oceania and Asia, but has not been studied extensively in tropical Asia.
Discovery a critical part of efforts to conserve our natural heritage
The discovery of Nervilia singaporensis continues the tradition by researchers of the Botanic Gardens in leading the study of our native plant species. It also highlights the importance of conserving Bukit Timah Nature Reserve. At 163 hectares, the Nature Reserve is only 0.23 percent the size of Singapore, and yet is home to more than 50% of native plant species found in the country.
David Middleton, Co-ordinating Director of Research and Conservation at the Singapore Botanic Gardens, said: “The plant diversity of Singapore has been widely researched compared to many parts of the tropics, so people might assume that everything about our natural habitats is already known and recorded. The discovery of Nervilia singaporensis shows that there is still unknown biodiversity to find and study, even in heavily urbanised Singapore. As such, continued efforts in documenting and learning about the richness of our habitats is crucial to protect them and their abundant biodiversity.”
Before the discovery of Nervilia singaporensis, Singapore had four species of endemic plants comprising the Singapore Ginger (Zingiber singapurense), Hanguana rubinea, Hanguana triangulata and Splachnobryum temasekensis. The first three species are part of NParks’ species recovery programme to cultivate and reintroduce more of these plant species into the wild.
Zingiber singapurense is a ginger that was discovered in 2014 as part of a conservation project initiated by the Singapore Botanic Gardens. There are only five populations of the plants in the Central Catchment Nature Reserve and this species is classified as critically endangered.
Hanguana rubinea and Hanguana triangulata are two species of forest plants that were discovered in 2015 by researchers from the Gardens. The two flowering herbs are classified as critically endangered at national and global levels, with populations restricted to a few sites in Singapore. Hanguana rubinea can only be found in Bukit Timah, Mandai, MacRitchie and Seletar, while Hanguana triangulata can only be found in Bukit Timah and Seletar.
Splachnobryum temasekensis is a tiny moss that can only be found in Singapore’s urban areas. Its wild habitat is still unknown, and its small size – ranging from being the size of a 5-cent coin or smaller – and superficial resemblance to other common species of mosses make it difficult to find.
The existence of these endemic species gives us impetus to protect and conserve our natural heritage. As such, with the aim of making Singapore a City in Nature, the National Parks Board, of which the Botanic Gardens is a part of, is working to restore natural habitats in our parks, gardens and nature reserves, as well as create nature parks as buffer areas to protect our nature reserves from the effects of urbanisation.