Ruellia has been a long time favorite. It was one of the first really rare plants I saw locally. In 1976, I took a continuing ed course from Prof. Herb Wagner from the University of Michigan. He was the one who reported Ruellia in 1957. I was a little surprised that his directions were not spot on. Now that I'm the age he was then, I understand. The original sites are now much more mature woodlands than they were in 1957. The new site is more open, partly due to ash die off. The number of plants at the new site seems to be increasing, while the old site is almost gone. It is a shame, because they are in completely separate drainage Of course, there could be more in the original area that we didn't find.
Ruellia has flowers like the one used in today's posting, and ones that don't open and self fertilize like the one above. In 2012 we had a severe drought. The new site, mostly a floodplain, was completely dried up with the ground shrinking and leaving fissures. In that year I could find no open flowers, only self fertilizing ones. The following year was a flood year, with the site under several feet of water into July. That did not seem to affect the population. They are all still thriving.
Ruellia is a fairly common garden plant. It has two drawbacks. With its tendency to self fertilize, flowers are not abundant. Although they can be increased by plant selection, and good care. Secondly, the roots are like iron. Weeding the numerous seedlings is almost impossible.
Ruellia flowers are resupinate. This means as they open, they rotate 180 degrees. The top of the open flower is the bottom of the bud.