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.

New records

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.

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.