I am not familiar with Dendrochilum williamsii, but here are basically the conditions
http://www.orchidspecies.com/d...
Should be ok in your hands. I find most Dendrochilums not too fussy. But I do water a lot, def. in Winter with rain water.
Pleurothallis ruscifolia
http://www.orchidspecies.com/p...
I think you should be ok too.
I like this website to check out species. Through the years I find that pretty much all Masdevallias and many Pleurothallis can't take the NJ Summer for too long, but some Pleurothallis are surprisingly resilient.
