Petal postgenital

Fig 8.2 Peganum harmala. Floral bud, transverse section series. Sepal basal lateral appendages marked with asterisks [ ]. (A) Distal zone, live sepals and five petals with contort aestivation. (B) Fifteen stamens surrounding three carpel tips [c], free but postgenitally united. 

At anthesis, the sepals and petals are fully expanded. The petals are no longer postgenitally connected. Nectaries are situated between the androecium and gynoecium, where they form five depressions in the petal radii (Fig 8.2E). After anthesis, the sepals are persistent. The petals and stamens fall off. The long style dries up distally, but also persists for some time and no abscission zone can be seen at anthesis. 

Fig 8.6 Nitraria retusa. Floral bud, transverse section series. (A) Distal zone, five petals [p] with valvate aestivation and tips bent inwards surrounding postgenitally united carpel tips [c]. (B) Fifteen stamens surrounding the style. (C) Ovary at the level of the placentae. (D) Ovary, with two fertile locules, each with one ovule [o], and one sterile, empty locule [si]. (E) Floral hase, with five antesepalous depressions (nectaries). Scale bars (A)-(E) = 1 mm. 

Flowers of the genus Acacia s.l. are always found in globular heads or spikes. The flowers are (3-)4-5(-6)-merous, with free or united sepals and small reduced petals, which are postgenitally fused and which split open at anthesis. The androecium is... 

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