The families of flowering plants.
Habit and leaf form. Herbs. Perennial; rhizomatous (the rhizome slender, branched, scaly, with a solitary leaf and flower arising from each bud). Leaves long petiolate; simple. Lamina dissected; palmatifid (with five major, cuneate segments, these variously lobed and toothed); with radiating, dichotomous venation; without cross-venules (the venation open). Leaves exstipulate (?).
Reproductive type, pollination. Plants hermaphrodite. Floral nectaries present. Nectar secretion from the androecium (from the staminodes).
Inflorescence, floral, fruit and seed morphology. Flowers solitary; axillary (on long scapes); small; regular. Free hypanthium absent. Hypogynous disk absent.
Perianthpetaline; 4–7; free.
Androecium11–21. Androecial members free of the perianth; free of one another. Androecium including staminodes. Staminodes 8–13; external to the fertile stamens (representing the outer members). Stamens 3–6. Anthers dehiscing via longitudinal slits; bilocular; tetrasporangiate.
Gynoecium 4–9 carpelled; apocarpous; eu-apocarpous; superior. Carpel stylate (the style short, persistent, deflexed in the fruit); 1 ovuled. Placentation apical to marginal (ventral, subapical). Ovules pendulous; orthotropous.
Fruit non-fleshy; an aggregate. The fruiting carpel indehiscent; an achene. Seeds endospermic.
Geography, cytology. Holarctic. Temperate. North and West China.
Taxonomy.Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Ranunculiflorae; Ranunculales. Cronquist’s Subclass Magnoliidae; Ranunculales. APG 3 core angiosperms; peripheral eudicot; Superorder Ranunculanae; Order Ranunculales (as a synonym of Circaeasteraceae).
Species 1. Genera 1; only genus, Kingdonia.