Clermontia calophylla is supposed to be closely related to clermontia parviflora. I'm not sure if I've seen this species yet. I put these Upper Hamakua Ditch clermontias in this gallery because that their foliage has a similar amount of purple in the new leaves as in c. parviflora, but these also have a distinctive silvery-blue color. Their flowers look a bit different than the usual c. parviflora flowers. Hopefully I'll get a better handle on the Kohala species in the future.