The leatherleaf orchid
The leatherleaf orchid, Aerides crassifolia (Orchidaceae) is restricted to the drier parts of Southeast Asia where it inhabits deciduous savannah-like forests.
The Dokmai Garden specimen was originally mounted on a piece of hardwood, and when I decided to move it from the nursery to the woodland, I was afraid I should accidentally hurt its roots by removing them from the original substrate. It is the only specimen of the Orchid Ark so special attention was needed. I tied the whole clump to the stem of a Dipterocarpus alatus in an area we never irrigate. In the storm a month ago the orchid with its heavy fundament must have fallen down, and only thanks to its pink blossom pleading for help amidst a sea of decaying leaf litter, it was discovered and saved from certain death. My lesson learnt: always detach the orchid from the pot/net/wood and tie it using at least two natural fiber strings to the tree. When removing the roots from the original substrate, gently push them sideways, do not grab the root tip and pull it as if the aerial root was made of tape. By transferring orchids to the trees in your garden in the early rainy season (now) you will give the orchid the possibility to firmly attach itself with its own roots. Always map your orchids in case tags disappear and in case branches or orchids fall down, and frequently monitor them (dog walking is good).
A general rule for orchids exposed to sun and drought is that they reduce the leaf surface to save water. The leaves are often cylindrical (terete). The leatherleaf orchid (crassifolia means ‘thick leaf’) is an exception, but its broad leaves are fat, almost succulent, and might be a stage in evolution towards reduced surface and increased volume.
There are many more native orchids in blossom at Dokmai Garden right now. The avatar orchid Vanda flabellata which was transferred to the monsoon woodland last year blooms happily, and it amazes me how such a dusty dry habitat fits them so well. I can also proudly report that the pollination of Vanda denisoniana was successful and we anticipate a beautiful harvest of orchid fruits and seeds.
The flower of Aerides crassifolia looks like a pink eagle. Its beauty makes it a vulnerable target for orchid thieves who steal them from the national parks and sell them along roadsides. Another very similar orchid genus with eagle-like columns is Rhynchostylis. The flowers of that genus have tongue-like lips, while members of Aerides have 3-lobed lips. Some Aerides have been moved to the genus Vanda, which is why vernacular names should not contain the genus name.
Text & Photo: Eric Danell