Habenaria carnea N. E. Brown belongs to the family Orchidaceae. This species has only been collected from the forested limestone outcrops of Perlis and Langkawi Island in Malaysia; and Peninsular Thailand. In Perlis, Habenaria carnea is commonly found growing on shaded and damp forest floor. This species becomes dormant during the annual drought (from January to March) as do other deciduous orchid species. The above-ground vegetative parts of the plant wither and die after flowering, leaving the tuber dormant below the ground. Buds at the tip of the tuber begin sprouting at the onset of the warm and wet season (from April to September), forming a new leafy shoot with a terminal inflorescence. It has beautiful pink flowers, spirally arranged, on a rachis.
Formerly, the leaves of Habenaria carnea were described as being olive green with whitish dots, with one variety having unspotted green leaves in Holttum (1964) and Seidenfaden and Wood (1992). However, we have since discovered that the leaves of Habenaria carnea change colour when the plant begins to flower. Juvenile plants collected in August 2003 from Bukit Rongkit had brown leaves with whitish spots at the time they were collected. Two of the juvenile plants were then transplanted to the greenhouse at the Department of Biology, Faculty of Science, Universiti Putra Malaysia, for further observation. When the plants began flowering in September 2003, the colour of the leaves gradually changed from brown with whitish spots to green with whitish spots. By the time the flowers were in full bloom, the leaves were all green with whitish spots (Yong, 2006). The cause of the change in leaf color observed above is not completely understood. To date the variety with unspotted green leaves mentioned by Holttum has not been found in Perlis.
Habenaria carnea has been collected from the wild for use in the ornamental plant trade. Orchid hobbyists and growers find the plant appealing due to its decorative leaves and attractive flowers. Uncontrolled collection of the species from the wild is therefore the main threat to its survival. Conservation action is needed to ensure that sustainable populations continue to survive and flourish in our Malaysian limestone forests.
