Clematis.
NOID:
'Henryi':
'Pink Climador':
'Fireflame':
Louisiana Iris.
'Jeri', which is a reddish "grape" purple:
Last year, I planted two more varieties of Louisiana iris-- 'Ann Chowning' (red) and 'Black Gamecock' (very dark purple). The former didn't bloomed this year (still getting settled in, I imagine), but one or two 'Black Gamecock' did. It's not quite as dark as I'd hoped, but it's still a beautiful flower with a slightly more bluish purple than 'Jeri'-- and a bigger yellow signal.