The plants are currently flowering again, this time even more vigorously, and I decided to post some photos on Facebook to see if anyone else had any ideas. Various suggestions we had already exhausted flowed in, but then Aaron Floden, a botanical taxonomist at Missouri Botanical Garden, confidently chimed in with “Hemiphylacus.” Since I had never heard of this genus, I looked it up and sure enough found a few photos in habitat of a plant that resembled ours spot-on, named Hemiphylacus hintoniorum.
Researching further, the current genetic studies show the genusHemiphylacus is a direct relative of Asparagus – yes, the edible vegetable. The two genera are the only ones recognized in Asparagaceae subfamily Asparagoideae. Though they look completely different, one similarity they both share are thick, fleshy nodular roots, as anyone who has grown “asparagus fern” (Asparagus aethiopicus) likely knows. Hemiphylacus dies back to this mass of roots in winter, but erupts out of the ground in spring with a refreshed rosette of clean silvery blue.