Morphology Of Flowering Plants - Placentation

Placentation describes the arrangement of ovules within the ovary, and NCERT recognises marginal, axile, parietal, free central and basal types. In axile placentation the margins of the carpels fuse to form a central axis, and the ovules are attached to this axis in a multilocular ovary, as seen in china rose, tomato and lemon; the presence of septa creating several chambers is its hallmark. Marginal placentation, as in pea, has a single chamber with ovules arranged along the ventral suture, lacking a central axis. Parietal placentation, as in mustard and Argemone, bears ovules on the inner ovary wall, and although a false septum may appear, the ovules are peripheral, not on a true central axis. Free central placentation, as in Dianthus, has ovules on a central column but the ovary is unilocular without septa. As stated in NCERT Class 11, Chapter 5 (Morphology of Flowering Plants), axile placentation occurs in a multilocular ovary with ovules on the central axis. A structural check confirms that septate multilocular ovaries with a central axis correspond only to axile placentation.