Tradescantia Andersoniana Group includes a number of named cultivars, but the distinction between these plants and those known as Tradescantia virginiana or T. x andersoniana is perplexing. They are rather fleshy, clump-forming perennials (ht 30-50 cm) from North America, with rather untidy, long, slender leaves, and unusual flowers comprised of three petals. They grow in full sun to part-shade. There are numerous named hybrids in various flower colours, including 'Snow Flake' (pure white), 'JC Weguelin' (pale blue) and 'Sweet Kate' (bright blue with lime-green foliage). There are also some dwarf forms with narrower foliage and a more compact habit, including 'Satin Doll', with bright pink-purple flowers (ht 30 cm). They generally bloom in summer and early autumn but may begin in late spring. They should be cut back hard whenever the leaves get too straggly, and fertilised in late winter. They are best grown at the front of garden borders so that they don't get swamped by other plants. Propagation is by division of the clumps in autumn or spring.
Postscript: I have since given up growing these plants in my garden, as I found they faded away after a while and never lived up to my expectations. I think they do better in cooler climates than mine.