barrenwort 'Flowers of Sulphur'

'Flowers of Sulphur' is a vigorous clump-forming rhizomatous perennial 35cm high, with deciduous, glossy, pointed leaves, which emerge red-bronze with green veins in spring, mature to apple green, and flush copper bronze in autumn, and large flowers of pale yellow sepals and spurred yellow petals, from mid to late spring; Epimedium leaves may be used for their nests by leaf-cutting bees