Of the four species of Hibiscus (Malvaceae) that grow in the Maryland Piedmont, two are alien (rose of Sharon and flower of an hour), and two are native. Starting in mid-July every year, I spend hours scouring the banks of the Potomac looking for these big, showy flowers.
Not that they’re hard to find. Despite being listed S3 (“At moderate risk of extinction or extirpation due to a fairly restricted range, relatively few populations…”), I see Hibiscus laevis (halberd-leaved rosemallow) by the hundreds.
The tricky thing is getting a good angle to shoot them. Halberd-leaved rosemallow is a wetland obligate, and with the flowers usually facing the river, the water level has to be low for me to get close enough to take decent pictures.
Hibiscus moscheutos (swamp rosemallow, crimson-eye rosemallow) is also a wetland obligate. It should be more common than H. laevis, but before this summer I had only seen them in the C&O Canal. This year I found several along the river banks.
The flowers of both species are about the same size. H laevis generally sports pink flowers, but they can be very pale, almost white, while H. moscheutos flowers are generally pure white. Both have a crimson throat. Color isn’t a reliable way to distinguish between them, though. Instead look at the leaves.
<—Hibiscus laevis leaf
Hibiscus moscheutos leaf—>