More new plant species could emerge, thanks to Singapore herbarium

Scientists say discoveries of new flora have been possible because of a rich repository of records that sit in a herbarium at the Singapore Botanic Gardens.
Monica Kotwani, Channel NewsAsia 2 Jul 15;

SINGAPORE: The National Parks Board (NParks) announced the discovery of two new plant species in June, and experts say more species could emerge over the next few years.

This is despite Singapore's tropical flora already being one of the best researched in the world. Scientists have said such discoveries have been possible because of a rich repository of records that sit in a herbarium at the Singapore Botanic Gardens.

DISCOVERING NEW SPECIES

NParks' principal researcher of plant taxonomy Dr Jana Skornickova came across what she thought were different species of Hanguanas. But records contradicted her find, as they showed only one species, the Hanguana Malayana, existed. She and her team monitored the Hanguana plants at the Central Catchment Nature Reserve for three more years, until they flowered and bore fruits.

She then compared them to a dried Hanguana fruit specimen kept at the Singapore Botanic Gardens herbarium. The specimen had been collected by the Gardens' first director, Henry Ridley, in 1890.

"This is quite amazing because you can actually do it with the herbarium specimens from Henry Ridley's time,” said Dr Skornickova.

“We soaked specimens from 1890. All you do is take one fruit, put it in room temperature water overnight, and next day, you can easily peel off the pulp, you can take out the seed, excavate the seed because Hanguanas are unique in the plant kingdom by having a bowl shape to almost closed-bowl shape seeds, and you need to dig out the insides of the bowl to see everything. That's when we discovered that seeds are actually quite distinct in different species."

By comparing the seeds, two new Hanguana species were identified - the Hanguana rubinea and the Hanguana triangulata.

Dr Skornickova also realised that even though records stated only one Hanguana species existed before, she said Ridley knew there were more, just that he never got round to working on it. She pointed to a note he made on the specimen record, where he left the name as just Hanguana. The word “Malayana” is thought to have been added by another botanist.

Dr Skornickova said Ridley's records have helped scientists understand the extent of environmental changes in Singapore. Ridley found the species in three different locations. But the two new Hanguana species are now only found at the primary forest in the Central Catchment Nature Reserve, which includes a trail along the MacRitchie Reservoir.

Last year, Dr Skornickova also discovered a new ginger species native to Singapore. She said more discoveries are likely as research on flora has now shifted back to alpha-taxonomy, which is the discipline of detecting and classifying new species.

But these discoveries have been made easier, thanks to the herbarium, which houses more than 750,000 dried specimens and 15,000 spirit collections of plants across Southeast Asia.

"Most of the botanists who work in Southeast Asia, they basically cannot skip the Singapore herbarium because of the historical collections here,” said Dr Skornickova. “Everyone who works for almost any plant group needs to refer back to the original materials by Henry Ridley. Basically the researcher has no choice but to come to Singapore. So in that sense, Singapore herbarium is really part of our national heritage."

Dr Skornickova added the herbarium has played a critical role in the understanding of Southeast Asian flora.

- CNA/xq

Two newly discovered plant species and other gems of Singapore's flora
Audrey Tan Straits Times 10 Jul 15;

For more than a century, 26 plant specimens tucked away in the Singapore Botanic Gardens suffered from a case of mistaken identity.

The flowering herbs had been mislabelled Hanguana malayana, a black-berried plant often found growing by water. Researchers at the Singapore Botanic Gardens discovered last month that the specimens were actually two different Hanguana species new to science and unique to Singapore - the Hanguana rubinea and Hanguana triangulata.

Here's a close-up look at the two newly-discovered plant species and other precious finds in Singapore's botanical landscape.

Plants found only in Singapore

Hanguana rubinea: One of two species of plants new to science discovered by researchers at the Singapore Botanic Gardens this year. It has ruby-red fruit, from which it gets its name. The plants are found only in primary forests in four areas - Bukit Timah, Mandai, MacRitchie and Seletar. Habitat disturbance is a major problem for this critically endangered species.

Hanguana triangulata: The other plant species new to science discovered this year. This white-berried herb is named for the sharply triangular shape of the stigma (female part of the flower). It is critically endangered and can be found only in primary forests in Bukit Timah and Seletar.

Zingiber singapurense: Discovered last year in the Central Catchment Nature Reserve, this species of ginger has red and white flowers. It is named after Singapore's name in Malay - Singapura.

Bruguiera hainesii: This critically endangered mangrove tree native to Singapore is also known as the Eye of the Crocodile. It was first discovered here in 2003. Out of 200 such trees in the world, two were found on Pulau Ubin. But since then, they have been planted in various places, including Sungei Buloh Wetland Reserve.

Hoya caudata: This critically endangered climber has wiry stems only about 0.3cm thick. It was first documented in the Nee Soon Swamp Forest by researchers from the National Parks Board and National University of Singapore in 2012.

Dr Jana Leong- Skornickova with a leaf from the Hanguana rubinea plant. The ginger plant specialist stumbled upon the new species while on a routine field survey at the Central Catchment Nature Reserve in 2012.

Rediscovered

Pterospermum diversifolium: This tree native to Singapore was first documented in Pulau Ubin in 1890. It was rediscovered on the same island by NParks researchers in 2013.

Bulbophyllum singaporeanum: This orchid was first collected in 1896 by British botanist Henry Ridley. It was then presumed to be nationally extinct. But the orchid, recognised by its long green leaves and magenta and green flowers, was re-collected from Nee Soon Swamp Forest in 2009.