I found two daylily farms each about a two-hour drive from my house. Once or twice a year I can tolerate a two-hour drive. I have visited Thumper's Daylily Farm (now called Sonrise Flower Farm) several times and when my Clementella started blooming in May I called them and asked if they had any plants in bloom. Sure enough they did so off I went and bought Dr Regel (a dead ringer for Dumortierii) and an unregistered variety they call Chubby Sam.

Dr Regel

Chubby Sam