adjective
BotanyHaving only one series of perianth segments, i.e. not having the perianth differentiated into corolla and calyx; specifically (now rare) belonging to the Monochlamydeae, a division or subclass of dictyledonous plants having flowers with only one series of perianth segments or sometimes no perianth, including the Chenopodiaceae, Euphorbiaceae, etc.
Origin
Mid 19th century; earliest use found in John Lindley (1799–1865), botanist and horticulturist. From scientific Latin Monochlamydeae, group name (from ancient Greek μονο- + χλαμυδ-, χλαμύς) + -ous.
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