Ground Orchids (Terrestrial Orchids)
Not surprisingly, ground orchids are found growing in soil, unlike their tropical brethren that we are accustomed to thinking as orchids, for example the genus Cattleya. The name "ground orchid" itself is a misnomer, and even then the more technical term, terrestrial orchid, is in part inaccurate. The reason why has to do with the substrates these highly varied plants are found in naturally. Some are found in loamy soils of forests, while others colonize old sand dunes. Others still grow in boggy, peat-based mucks on seepage slopes or out on mats of peat bogs floating on old glacial lakes. Others can be found in mineral-based soils, such as Cypripedium californium which grows in serpentine soils of seepage bogs in northern California and adjoining areas of Oregon. The terrestrial orchids native to the pine rocklands of south Florida's Everglades region grow in a thin layer of organic debris overlaying pure limestone rock and marl. So again, we can see that diversity within any category of plants is often extreme, and generalizations are not adequate in describing them.
Probably some of the best known terrestrial orchids are in the genera Bletilla, Cypripedium, and Orchis. Many have gotten the name hardy orchid because some colorful flowered species are found in temperate regions. Of course not all terrestrial orchids are from temperate climates, in fact, they can be found as far north as the Arctic Circle and all the way down to the very south end of Patagonia. They live in any climate zone, from tropical to subarctic. Not surprisingly, their cultural needs are equally as varied.
The focus here then is about specific groups - their natural history, biology, and cultivation. It is this last point that is of great interest to many adventurous souls. I say this because if you travel down the road of terrestrial orchid cultivation, you are in for a ride, with lots of highs and lows. Virtually no terrestrial orchid is actually easy except for a handful - Bletilla striata and Spathoglottis plicata pop into mind. If your growing conditions are right, you will find many others that too could be called easy - genera such as Dactylorihza and Pterostylis have members that fall in that category. Many more are challenging - the vast bulk of the popular genus Cyripedium, many of the acidic bog species, and most of the tropical jewel orchids all need more care and attendance to than a typical tropical orchid. Others still defy cultivation completely, at least under normal growing conditions - these would include all of the chlorophyll lacking saprophytes, and yet others such as Cypripedium irapeanum and related species from Mexico and Guatemala. A rare few can be called truly weedy, but some in the genera Spiranthes and Cynorkis fit that bill.
Fascinating, often strange, and sometimes familiar, this is another amazing group of plants to explore.