It is indeed always leafless. The plant consists of the flowering stem, which does not necessarily come up every year, and a large, branched rhizome (hence, macro-rhizon). It has limited roots and no pseudobulbs. It is symbiotic with various fungi groups to obtain its nutrition, and these in turn are associated with particular trees. Last I heard, the associated fungi have been identified, at least in Japan, and now which trees which are involved is being researched. Ah, pure science, a rare thing. I wonder who's funding that research? Must be very low budget and government money.
In Japan there are a bunch of mycoheterotrophic orchids, and by extension, there are even more throughout Asia, in particular SE Asia. This species has been divided into several species in Japan historically, C. aberrans and C. nipponicum, and of course C. macrorhizon. It appears that C. nipponicum is a synonym, and C. aberrans is a white flowered form of the species. I can't speak to other associated species except C. lanifolium, which of course has leaves, and is closely allied. Lovely, odd little orchids to be sure.
And since the first one I found was in the path, I almost did step on the poor thing!
I did actually try to smell it Angela, and at least the ones I sniffed had no odor. No idea on the pollinator, but given their proximity to the ground and deep forest conditions, I'd wager a beetle or crawling insect of some sort.
Rudolf, this species has been placed in numerous genera over the years, but recent studies place it into Cymbidium, albeit an oddity within the genus.