Pigeon orchids - so called because the flower buds look like little white pigeons - were flowering profusely in Mandai Road on Monday. This native orchid, Dendrobium crumenatum, is one of the more common epiphytes in Singapore. The flowers are white with a yellow-tinted throat, and typically last less than a day.

"With Dendrobium crumenatum - the pigeon orchid - all the plants in an area flower at the same time - nine days after a heavy rainstorm. The drop in temperature that typically happens after such rains triggers the flowering of this orchid. The colour and fragrance of the massive number of flowers then attracts bees, which cross-pollinate the orchids", said Dr Yam Tim Wing, principal researcher of the Singapore Botanic Gardens, National Parks Board. "Since most of the orchids that flower in this manner last for only one day, it is important that they flower all at once, for the best chance of cross-pollination."

Pigeon orchids have also been spotted flowering on rain trees on the Pan-Island Expressway, in Bishan Park and in other areas.