A blue-bell gentian, Eustoma grandiflorum
(click to enlarge)
These summer flowers are spectacular and uncommon. I found this one growing by the banks of Onion Creek. This flower is about 2 1/2 inches across and there were several flowers on the plant. The plants are about 2 feet tall. It is one of our wildflowers that should find its way into people's gardens, but I have never seen one in a domestic setting. I gathered a few seeds once years ago with the intention of trying to grow them, but I must not have cared for them properly, because they did not sprout.
Though I only run across a few every summer, they are not as far as I know endangered, and are a pleasure to find in the wild.
A quick google search tells me that they are in fact found in the horticulture trade. That's probably a good thing, because, unlike some cactuses, people don't dig these up in the wild to domesticate them. They are a native flower of the southern plains, and their uncommonness probably is due to their preference for moist environments, had to come by around here, certainly.