Euphorbia

A large genus of herbs, succulents, shrubs and small trees, but of the species that can be counted as woody few are hardy in our climate. Indeed, the species treated below, with the exception of E. mellifera and E. dendroides, scarcely qualify as shrubs and might more properly be regarded as perennial-stemmed herbs. The apparent flower of Euphorbia is a condensed inflorescence known as a cyathium. The single pistillate flower is stalked and lacks both petals and calyx; male flowers numerous, each reduced to a single stamen; the whole surrounded by a calyx-like involucre, with glands between the lobes. The most conspicuous part of the total inflorescence is (in the species described) the pair of opposite bracts that subtends each cyathium.