Napaea dioica

Totally neglected in the UK, yet a splendid North American native, this bold mallow deserves much wider planting. Superb much divided, Ligularia-like palmate foliage makes a striking clump up to about 1m across, giving rise to upright flowering stems to about 2m potentially, topped by tight clusters of smallish white mallow flowers. Easy in a not too dry position in sun or semi-shade.