Singapore added five species of plants that have not previously been recorded in the country in 2021.
1. Lepidogyne longifolia
This plant from the Orchidaceae family is considered native to Singapore and is also known to be native in parts of Johor and Sumatra.
A small population was first discovered in Bukit Timah Nature Reserve in 2019, consisting of likely only three individual plants. In Singapore, the plant is found in the shade of the forest understorey and in the fully saturated soil of a freshwater swamp.
2. Ptyssiglottis kunthiana
This plant, of the Acanthaceae family, is considered native to Singapore, where it grows in humid shade among large natural boulders in the primary forest of the Bukit Timah Nature Reserve. It is also known to be native in parts of Johor and Sumatra.
Although the plant is assessed as a species of least concern globally, there is only one small population found in Singapore, consisting of only 100 to 200 individual plants with a restricted distribution of about 20m by 70m.
3. Thysananthus ciliaris
This liverwort species was discovered in 2020 growing among other tiny plants on the buttress of a Terminalia subspathulata heritage tree, during a survey in the Singapore Botanic Gardens. The plants form in a mat with each shoot reaching up to 3cm long, and 0.8mm to 1.5mm wide.
NParks said it is a "rare and poorly known species from Southeast Asia", with just five verified collections recorded. It is globally endangered and nationally critically endangered.
4. Ficus subulata
This species was collected several times between 2005 and 2021 from secondary forest on Pulau Ubin, but was only recently identified as the genus Ficus is particularly large and complex, said NParks. It has not yet been found on mainland Singapore.
It can be found as a creeper, growing in or on rocks, as a shrub or as a root climber growing to about 8m high on a host tree.
A widespread species considered native to several countries in the southern and eastern regions of Asia, this plant is assessed as a species of least concern globally, and critically endangered nationally.
5. Visia cylindrocellularis
Formerly thought to exist only in Pahang, this is the only known freshwater red algae species in Singapore. It was discovered in 2018 in a forest stream of Bukit Timah Nature Reserve and is assessed as nationally critically endangered.
The discovery extends the distribution of Visia cylindrocellularis considerably southwards, said NParks, adding that future research will contribute to a better understanding of the diversity and distribution of this group of red algae.