Seeds from this endangered Prairie Spiderwort Tradescanta bracteata. This Herbaceous perennial Family Commelinaceae is hardy in zones 4 to 9 and is getting increasingly hard to find in the wild and is listed under the endangered species lists. This plant grows 18 inches tall and 2 feet wide with these lavender blue blossoms in May and July. Grow in average, dry to medium moisture, well drained soil in full sun.