Soterosanthus shepheardii

This month, the darkest in recent memory, our Soterosanthus has been illuminating the greenhouse with flower spikes like sparklers. Or a holiday candelabra.

Soterosanthus shepheardii is perhaps one of the rarest tropical orchids in our collection. Most of the year it keeps its head down and passes for a Kegeliella, which it resembles vegetatively. Same size. Same thin textured plicate leaves, green on the upper surface and purple below. So I was startled in December to see five erect spikes with extraordinary flowers. Notice the lip in the 12 o'clock position; and the dark downy hairs on the spike and pedicels. (Sorry about the grainy blue-grey images. Did I mention that we've had 16 weekends in a row of rain?)

Soterosanthus is native to the Choco region of northwest Ecuador and southwest Colombia. It grows as an epiphyte in coastal mangrove forests or on the trunks of large trees in pluvial forests, according to Native Ecuadorian Orchids.

It first appeared in Europe in 1897 when Friedrich Carl Lehmann (19th century Prussian mining engineer, amateur naturalist and plant collector. More about his fascinating life here.) posted plants, drawings and a herbarium specimen to England. The original Latin name, Sievekingia shepheardii, was published with a description by R.A. Rolfe (distinguished botanist at the Kew herbarium and founder of the Orchid Review) in 1915. Soterosanthus is a monotypic genus--just one species.

We keep our Soterosanthus on the moist side, as we do with many of our orchids from the Choco region. It grows well in our warm greenhouse in 80% shade, potted in a net basket  in a medium of premium sphagnum and coarse chopped tree fern fiber.