Autumn-flowering gentians provide a visual contrast to the season’s reds, browns and oranges. UBC Botanical Garden grows a fair-sized patch of these ‘Kingfisher’ gentians in the Alpine Garden near the entrance to the bed of Asian plants (photograph).
I’m not trained in garden design, but I’d like to imagine that if these were planted in combination with an orange-autumn-foliaged shrub or tree, the fallen leaves in combination with the blue gentian flowers would be very appealing (I’ve been fascinated with blue-and-orange combinations lately, though, so I’m perhaps blinded by that).
To read more about gentians, George L. suggested the link to the Gentian Research Network in comments to last month’s entry on Gentiana algida. For a shorter read, Wikipedia provides a summary of gentians.