Polyadelphia
/ˌpɒlɪəˈdɛlfɪə/Botany. Now historical
noun
In the Linnaean artificial system: the eighteenth class of plants, comprising those whose flowers have numerous stamens united by their filaments into three or more bundles.
Origin
Mid 18th century; earliest use found in Chambers's Cyclopaedia. From scientific Latin Polyadelphia, former class name (Linnaeus Systema Naturae) from poly- + ancient Greek ἀδελϕός brother + scientific Latin -ia.