This grower is sure of this plant identification.
From a woody rootstock comes a basal clump of large divided leaves. Strong branched stems are flung well above. They carry primrose-coloured scabious flowers with greenish centres, intermittently all summer. Thrives in heavy clay. H&S 6ft x 3ft
Cephalaria gigantea (Giant scabious). A spreading perennial native to Caucasus and Northern Turkey. It's 4,5cm long, dark green leaves are pinnatisect, oblong and toothed. Can grow to heights of 2.5m. Bright yellow flowerheads emerge in summer, approximately 5 cm in diameter.
They are fully hardy and will prefer sun and well drained soil.