Tibetan orchid planting bed
This unusual structure is a planting bed for the native Himalayan orchid Gastrodia elata, which is known in "Tianma." Tubers of this orchid are planted between cut stems taken from deciduous trees. Along the sides of this layout, wood chips in porous plastic bags are added. Tianma is a saprophytic perennial that does not carry out photosynthesis, but is fed by fungi, which live off decaying wood.
(Photo credit and many thanks to Daniel Winkler, West Sichua)