variants of B. thunbergii have dark red to violet foliage, such as B. thunbergii f. atropurpurea 'Admiration', and B. thunbergii f. atropurpurea 'Atropurpurea Nana'.

The flowers are produced singly or in racemes of up to 20 on a single flower head. They are yellow or orange, 3-6 mm long, sepals are usually six, rarely three or nine, and the six petals are in alternating whorls of three, and the sepals are usually coloured like