Flower morphology and development of the monotypic Chinese genus Anemoclema (Ranunculaceae)

The morphology and development of the flowers of Anemoclema glaucifolium were studied with light and scanning electron microscopy, and compared with related genera. In Anemoclema all floral organs are initiated in a spiral sequence, while phyllotaxis is irregular spiral. The young sepals are crescent-shaped, but the young stamens and carpels are hemispherical. The developmental sequence of the microspores in the stamens is centripetal, following the initiation sequence of the stamens. The mature ovule is anatropous and unitegmic. Our results support the inclusion of Anemoclema within Anemoneae based on the floral developmental and morphological features: carpels bearing one median fertile ovule and two or three lateral sterile ovules. Anemoclema also possesses traits that unify it with Clematis, that are lacking in Anemone : (1) centripetal anther maturation (vs. centrifugal or bidirectional), and (2) conspicuous appendage at the ventral base of the ovule funicle (vs. inconspicuous appendage). These characters support a close relationship to Clematis , which complement results from molecular inferences.