If you want a bullet proof flower for the Austin area try oxblood lilies.
When we first moved to this property very few living things had managed to survive not only a long term drought but more than a few years of being completely neglected. I found these oxblood lilies growing in a large clump hidden in VERY shady area under some overgrown shrubs. When I first saw them I felt like an anthropologist and thought they were a small sign that in ancient times a gardener must have lived here.
In fact, a gardener did live here. A few years ago I met one of my neighbours who grew up in our neighbourhood which dates back to the 1940s. He knew the original owner/gardener and showed me a few of the shrubs and trees he remembered helping to dig the holes for. I was really inspired by that conversation. I kind of hope that if the ghost of that gardener ever visits he would be happy to see that I love this little spot as much as he did.
Oxblood lilies are not native but they are one of the few bulbs willing to naturalize here. Like the rain lilies and cenizo, they are triggered by autumn rain. I learned today that they can live from 50-100 years! I believe it.