Looking through some photos we took at UBC last spring. We were visitin when the native garden was in peak bloom. Here is a spectacular form of our native trillium, Trillium ovatum 'Tillicum'
Looks pretty nice. Nothing about it in Case, Jr. & Case, TRILLIUMS (1997, Timber Press): "Double forms of Trillium ovatum have been reported in the horticultural literature. We do not believe that any has been properly named botanically. Such forms would be highly prized by gardeners and horticulturists within the region where the plants are fully hardy."
We know the garden does not propagate this cultivar, but Frasier Thimble Farms on Saltspring Island is reportedly working on several double ovatum forms through tissue culture.