Bob Hobden wrote:

There are close relatives that have no leaves and complete all their
photosynthesis through their roots which has always convinced me that giving
the Phal roots light must be beneficial to the plant, maybe not essential,
but beneficial.

I don't often keep up with taxonomic revisions, but I seem to recall
than many of the so-called leafless 'Angraecoids' were moved to the
Campylocentrinae leaving just a few aberrant genera such as
Microcoelia and Chiloschista, which are very close to Sarcanthus and
somewhat distant from Phalaenopsis. I grew M. Guyoniana for a few
years many moons ago. It consisted of an untidy, radiating cluster of
faintly orange-tinted grey roots most of which hung free with less
than half adhering to the bark on which they were growing. Absolutely
fascinating the way that these plants have done away with foliage and
exist solely as a mass of roots arising from a very abbreviated
rhizome.

The Microcoelia seemed to do well suspended just above a mist
propagator, in full light where contrary to the accepted rule of the
day for these orchids, temps occasionally fell to 10C in winter
without problems. It flowered once before I passed it on, producing
quite a few short, erect spikes of very tiny, glittering white
flowers. Very strange plants indeed and apparent success with this
had me trying to get hold of that ultimate and spectacular 'ghost
orchid' - Polyrrhiza lindenii for a while. Of course it never became
available. Nursery life took over and I had to content myself with
satisfying the needs of the suburban gardener rather than pander to my
own eclectic tastes.