Griffith's spurge

Description

Euphorbia griffithii, the Griffith's spurge, is a species of flowering plant in the spurge family Euphorbiaceae, native to Bhutan, Tibet and south west China. It is a spreading, rhizomatous herbaceous perennial growing to 90 cm (35 in), with many erect reddish stems and narrow dark green leaves with red central veins, turning red and yellow in autumn. In summer it produces flowerheads (cyathia) of brilliant red and yellow. It is a vigorous plant, and can be invasive. Numerous cultivars have been selected for garden use, including 'Dixter' and ‘Fireglow”. The Latin specific epithet griffithii refers to William Griffith (1810-1845), a British naturalist and botanist. The plants are annual, biennial or perennial herbs, woody shrubs, or trees with a caustic, poisonous milky latex. The roots are fine or thick and fleshy or tuberous. Many species are more or less succulent, thorny, or unarmed. The main stem and mostly also the side arms of the succulent species are thick and fleshy, 15–91 cm (6–36 in) tall. The deciduous leaves may be opposite, alternate, or in whorls. In succulent species, the leaves are mostly small and short-lived. The stipules are mostly small, partly transformed into spines or glands, or missing. In Euphorbia, flowers occur in a head, called the cyathium (plural cyathia). Each male or female flower in the cyathium head has only its essential sexual part, in males the stamen, and in females the pistil. The flowers do not have sepals, petals, or nectar to attract pollinators, although other nonflower parts of the plant have an appearance and nectar glands with similar roles. Euphorbias are the only plants known to have this kind of flower head. Nectar glands and nectar that attract pollinators are held in the involucre, a cup-like part below and supporting the cyathium head. The "involucre" in the genus Euphorbia is not to be confused with the "involucre" in family Asteraceae members, which is a collection of bracts called phyllaries, which surround and encase the unopened flower head, then support the receptacle under it after the flower head opens. The involucre is above and supported by bract-like modified leaf structures (usually in pairs) called cyathophylls', or cyathial leaves. The cyathophyll often has a superficial appearance of being petals of a flower.