@MattM not the petals which matter, but rather the calli. Very distinctive in this species, which has tall, crowded calli, compared to C valida which has shorter, more widely spaced calli.
@MattM there are often C valida right alongside, though! A colony I recorded the other day had both species interspersed, gotta look closely at those calli.
@mattm now that this species has finally been formally described, the petals do get a mention, and these petals are in fact quite unusually broad! Thought you might like to know. I'm changing this sighting to C valida for now as despite the calli, I think it may be a better fit afterall.