The pistil of Bertolonia marmorata Naud. (Melastomataceae)

The flower of Bertolonia marmorata, a small herbaceous plant from South Brazil, is epigynous, pentamerous except for the trimerous gynaecium, pentacyclic and diplostemonous. The ovary is fused to the perianth-tube basally, on cross-section it appears as an equilateral triangle, one corner of which is taken by a locule situated abaxially and epipetalous. The style is terminal, and the stigma simple, but around the style the walls of the ovary, especially their middle parts, extend freely upwards (Fig. 13). The axillary placenta is an awl-formed structure, projecting into the locule rather perpendicular to the pistil axis.