Like the vervains I wrote about yesterday, these two species are very similar – except for the color of the blossom and the shape of the leaf.
Halberd-leaved rosemallow is usually pink, and has a leaf shaped like, well, a halberd. Or at least someone once thought so. It certainly is distinctive.
Swamp rosemallow is usually white with a red throat. The leaf is rounded at the base, pointed at the tip, wider overall, and unlobed.
Both species can get tall – 6 feet or more – and are shrub-like in appearance.
Both like it wet and sunny. You’ll find the halberd-leaved rosemallow lining the banks of the Potomac river, vast stands of them.
(this is a tiny stand)
I have never seen swamp rosemallow along the river, but there are three easy-to-get-to spots to view it: C&O Canal locks 7, 8, and 10.
By the way, don’t be misled by colors. Both can vary quite a bit, especially in different parts of the country.
Of the 15 or so native species of Hibiscus in the continental US, these are the only two to be found in the mid-Atlantic Piedmont.