Potentilla recta L.
sulphur cinquefoil, rough-fruited cinquefoil
sulphur cinquefoil, rough-fruited cinquefoil
August 6,
Stony Brook Reservation, Boston
Yet another spoken name of this plant is rough-fruited cinquefoil. Its fruit, as in any cinquefoil, is a head of achenes, which is enclosed in the persistent hairy calyx.