Comparative Floral Ontogeny in Detarieae (Leguminosae: Caesalpinioideae). III. Adaxially Initiated Whorls in Julbernardia and Sindora

Abstract

The floral initiation of two detarioid legumes, Sindora klaineana and Julbernardia pellegriniana, deviates markedly from most legumes in that unidirectional order of initiation in some whorls starts from the adaxial side of the floral apex. In most legumes, unidirectionally initiated floral organs start abaxially. Each stamen whorl in both taxa starts initiation adaxially, and petals in Julbernardia also start adaxially. Both have the Omega assemblage of character states that includes a presepal floral apex wide in the sagittal plane and narrow tangentially and bracteole primordia broadly attached at initiation that enlarge rapidly to cover the floral bud. Both taxa initiate all 21 floral organs and have zygomorphic symmetry, a hypanthium, and four or five reduced petals. Sepal initiation is helical or modified helical in both, and petal initiation is unidirectional in both (from the abaxial side in Sindora vs. from the adaxial side in Julbernardia). Some organ whorls overlap in time of initiation in both...