Conservation, propagation and reintroduction of two-colored cymbidium orchid in Singapore

Summary

Cymbidium bicolor subsp. pubescens, an epiphytic orchid, was presumed extinct in Singapore after last being collected in 1891, until its rediscovery in 2000 at Sungei Buloh Wetland Reserve as a single surviving plant. Singapore Botanic Gardens researchers raised seedlings from seed collected off that plant, germinating them on a modified culture medium, growing them on in flasks for about a year, then in nursery pots for 12 to 18 months until each had three to four new shoots and a healthy root system. Because the species is epiphytic, seedlings were secured with wire or nails to the trunks and branches of mature host trees, mostly rain trees already carrying other epiphytes, in partial shade and timed to the rainy season from September to November so roots would establish quickly. Plantings since 2007 have spread from Sungei Buloh to the Singapore Botanic Gardens, Telok Blangah Hill Park, Dairy Farm Nature Park, MacRitchie Reservoir, Pulau Ubin and several roadside sites. Survival exceeded 80 percent at well-shaded, humid sites such as Dairy Farm and Central Catchment Nature Reserve, but exposed young mangrove trees and the high, wind-exposed Kent Ridge Park saw survival fall as low as 20 percent. Many reintroduced plants have since flowered and fruited, and the project is rated highly successful, having re-established a wild population from a single remaining individual.