Floral development in Anemoneae (Ranunculaceae)

Abstract

The floral development of two Clematis species and four Anemone species (including Pulsatilla) (Anemoneae, Ranunculaceae) is described. Shared features are: (1) sepals shortly after initiation broad, crescent-shaped, as opposed to the other organs, which are narrow and hemispherical; (2) outermost organs of the androecium often smaller than the others and sometimes sterile; (3) carpels ascidiate, with distinctive stalk, stigma papillate, decurrent; the carpels have one median fertile ovule and a few lateral sterile ovules in all species studied; the fertile ovule appears before the carpel closes. Generic differences are: (1) In Clematis, four sepals are initiated in two pairs; sometimes one of the sepals in the second pair appears to be divided into two organs (double position) resulting in a pentamerous perianth; the first eight stamens are positioned in two alternating whorls, the outer whorl alternating with the four sepals. In Anemone, the perianth organs, if five, are initiated in spiral sequence; in the Pulsatilla group of Anemone, six sepals are initiated in two whorls; the first three organs of the androecium (staminodes) alternate with the inner sepals. (2) Further androecial organs are mostly in complex whorls (i.e. including double positions) in Clematis, but in an irregular spiral or in irregular complex whorls in Anemone.(3) Anther maturation is largely centripetal in Clematis, but centrifugal or bidirectional in Anemone. In Clematis macropetala, the outermost organs of the androecium lack anthers and the filaments expand and become petal-like. In contrast, in the Pulsatilla group of Anemone, these organs retain sterile anthers and become small, capitate organs.

Stochastic occurrence of trimery from pentamery in floral phyllotaxis of Anemone (Ranunculaceae)

“…1d, II -top panel), respectively. The former shows spiral initiation similar to sepal development in core eudicots [6], while the latter arrangement is similar to monocots.…”

“…1d). Moreover, the intermediate initiation of spiral and trimerous patterns was observed in the genus [6]. Hence, variation of Anemone flowers may reflect the transient state of spiral phyllotaxis to a stable arrangement, including both three and five, in a fixed number of organs.…”

“…As in phyllotaxis [10], a new primordium arises within a vacancy between two earlier primordia during Anemone floral development [6], thus, there are five possible positions of the sixth tepal (Fig. 1d).…”

Integrating Early Cretaceous Fossils into the Phylogeny of Living Angiosperms: ANITA Lines and Relatives of Chloranthaceae

“…They suggested that the flower had a whorled arrangement that was distorted during fossilization. Based on their figures, we suspect that the flower is not distorted and its phyllotaxis was truly irregular, a condition that we score as unknown (except when phyllotaxis varies between irregular and well defined, as may occur within species; Ren et al 2010). We therefore follow Friis et al (2009) in scoring phyllotaxis of the perianth (54) and androecium (63) as unknown.…”

Morphology and vascular anatomy of the flower of Aconitum lasiocarpum (Rchb.) Gáyer subsp. Lasiocarpum (Ranunculaceae Juss.)

“…досліджувала-ся у різних аспектах протягом багатьох років та для різних видів [8,12,24,30,31,39,42]. Чимала увага приділялась особливостям онтогенезу квітки й організації провідної системи цих рослин [26,37,41]. Зокрема, дослідженням васкулярної анатомії квітки жовтецевих присвячена фундаментальна праця J.H.…”