The folks in Austin take their natural parks seriously and this is one of the better botanical gardens I've seen in the US. They've got a rose garden, an oriental garden, herbs and fragrant plants, cactuses. The Butterfly trail is filled with plants that attract those flying beasties.
If you're planning a visit check the website, which has a map and offers monthly photos of flowering plants and their identification so you'll know what to look for.
Open dawn to dusk.
