I am often asked ‘what are those round things on your orchids’. The answer is they are pseudobulbs. Orchids that live in monsoon climates have cleverly evolved to store water for use in the dry season. They do this by growing pseudobulbs which work on the same principle as a camel’s hump. They contain a clear honey like substance which if tested with iodine, turn purple showing they contain carbohydrate.
A healthy, well watered orchid should grow plump pseudobulbs which will gradually shrivel as the orchid feeds on the contents. Below is one of our Coelogyne cristatas modelling their healthy pseudobulbs.
Myrmecophila tibicinis, shown below looks like it has ridged stems with leaves at the ends but they are in fact large pseudobulbs. The name Myrmecophila comes from myrmecophile which is the name given to insects or plants that have relationships with ants.
Once empty the old pseudobulbs of Myrmecophila tibicinis are hollow and dry and make great homes for ants. In return for being given a cosy home the ants protect the orchid from predators.
Cattleya purpurata has long elongated pseudobulbs too. The orchid comes from Brazil where the summers are warm and wet but the winters are dry.
Coelogyne barbata grows in monsoon forests from Nepal to Southern China. We grow our plants in Cool asia watering well in summer with much less water in the winter.
Our Coelogyne fimbriata have much smaller pseudobulbs in comparison to their cousin Coelogyne barbata.
It was John Lindley ( 1799 – 1865), English botanist and gardener, who in the early nineteenth first invented the word pseudobulb to describe the orchid storage organ.