achene(redirected from achenium)
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achene(əkēn`), dry, simple, one-seeded fruit with the seed attached to the inner wall at only one point. Achenes are indehiscent, i.e., they do not split open at maturity. The so-called seed of a sunflower is an achene; the shell is the wall of the fruit, and the true seed lies within. A strawberry consists of many achenes embedded in a fleshy receptacle.
a monospermous indehiscent fruit of angiospermous plants. An achene consists of two carpels with an inferior ovary; it has a dry, leathery pericarp (in Compositae and Dipsacaceae). Winglike processes, pappi, hooklets, and other formations often develop to promote distribution of the fruit. The achene of Dipsacaceae falls off with a sheath of concresced bracts; in some Compositae (cocklebur, globe thistle) the achene falls off with the sheath of the head.