Flowering Spurge - detail of flower by cotinis

Detail showing structure of one flower--the "petals" are perhaps 6 mm across. The white "petals" are actually bracts, I believe. The female flower is the long-stalked structure jutting out from the center, and there are also clusters of male flowers at the base of the female flower stem--the yellow knobs. Aha! The Wikipedia article on Euphorbiaceae has a good description of the flowers, and I'll quote it here: Euphorbia and close relatives show a highly specialized form of pseudanthium ("false flower" made up of several true flowers) called a cyathium. This is usually a small cup-like involucre consisting of fused together bracts and peripheral nectary glands, surrounding a ring of male flowers, each a single stamen. In the middle of the cyathium stands a female flower: a single pistil with branched stigmas. This whole arrangement resembles a single flower. Thanks, Wikipedia authors! See also, the article on carpel, explaining the female parts of a flower. Euphorbia_corollataPCCA20070522-2556A

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