The
Evolution of the Stamen and the Carpel
Main trend of evolution in the stamens of angiosperms, from the most primitive, broad, leaf-life type (below, left) to the more advanced typical-looking, anther-filament type (below, right).
The primitive type of conduplicate (folded) carpel, unfolded in A to show its leaf-like nature with ovules borne along its surface in the area of the veins; folded in B as it actually occurs in the genus Drimys (Winteraceae), with the stigmatic area all along the side.
C to H indicate the main trend of evolution in carpels from the most primitive conduplicate type (C) with extensive stigmatic crest to advanced type (H) with stigmatic surface restricted to the tip of the style.