Euphorbia palustris, March Spurge is a showy herbaceous Euphorbia that grows rapidly in Spring and rewards with its bright acid-yellow flowers and foliage that turns yellow, orange and red in the autumn. A very easy-to-grow plant, Euphorbia palustris is one of the few Euphorbias that prefers a moist retentive soil rather than the more usual dryish free-draining substrate.

Euphorbias are the only genus in the entire plant kingdom to possess cyathia, a unique specialised pseudanthia or false flower which here, in the case of Euphorbia palustris group together in cymes to form a large inflorescence.

A cyathium is the floral envelope or involucre that surrounds each group of tiny true flowers - both male and female - consisting usually of simplified male flowers which have just one pedicel, anther and filament and a single female flower in the center comprising of a pedicel, a three-part ovary and no petals. The involucre usually has specialised leaves called cyathophylls or cyathial leaves that surround the cyathium and give a flower-like appearance to the inflorescence.