A genus of 4 species of orchids, related to Oreorchis and Aplectrum. These all make a corm-like pseudobulb and a solitary, pleated, wintergreen leaf. They are plants of deciduous woodland, growing when the leaves are absent from the trees but going dormant when light and water levels fall in summer.
A new leaf appears in late summer and lasts until mid winter or early Spring, building a new corm at its base. The plant then flowers, the old corm rots away and the plant goes dormant. The trick to successful cultivation is keeping the leaf green long enough to make a big new corm. If shrinkage happens too often then it fades away over a period of years. I have seen some imagined saprophytic relationship blamed for this, but I do not give credence to it. It is the grower's skill that counts.
Give full light when in growth from Autumn to Spring, shade from late spring to autumn. A very fertile soil with plenty of water in Autumn and Spring (drier, but not dry, in winter) and lots of humus. Leaf litter on the soil surface helps and cool humidity is beneficial. Think 'mossy-ferny' conditions. Not impossible, though not for beginners.