Coelogyne trinervis is a warm-growing species from Thailand and its surrounding areas, found at altitudes of up to around 100m. Although this species grows in deciduous forests in its native habitat, it does not require a cool rest, since the trees in which it grows are deciduous during the dry season. As such, it is encouraged back into growth by the onset of rain. In cultivation, it is not necessary to dry this species out in order to flower it, and it will quite happily start growing again as soon as the last cycle is completed. My plant does not rest at all.
The pseudobulbs are an olive-green colour and quite large. They are separated by several centimetres of rhizome, making this a creeping species that grows well in baskets. The leaves are three-veined (hence the name trinervis) and seem quite variable in size. My plant had quite broad, long leaves when I purchased it, but it has since produced much smaller leaves, probably in response to the high light intensity I use to grow it. The size of the pseudobulbs has remained consistent, or even increased slightly.
It flowers off new growth before leaves emerge. The inflorescences grow quite fast and will be in bloom within a few days of emerging. The flowers themselves are attractive enough, if a little drab, and are off-white with brown markings on the lip. There are up to 8 flowers per inflorescence. The blooms are very powerfully scented, and can be smelled some distance away. Sadly, the scent is not at all pleasant.
All in all, a rewarding species to grow if you have the space and a peg for your nose; otherwise it would be wiser to grow something else!