Arrangement of ovule within the ovary is placentation. Types of placentation are:
| PLACENTATION | FOUND IN OVARY | DEFINITION |
| MARGINAL | Monocarpellary unilocular ovary | Placenta develop and ovules are born along the junction of the two margins of the carpel.ex Pea |
| AXILE | Bi or multicarpellary & multilocular ovary | Margins of carpel fold inwards fusing together in the centre of ovary where the placenta are formed .The ovules are born at the centre on the placenta in each locule.Ex Hibiscus |
| PARIETAL | Bi or multicarpellary & unilocular ovary | Ovule develop on the inner wall of ovary or on peripheral part.Ex. Mustard |
| FREE CENTRAL | multicarpellary & unilocular ovary | Placenta develop in the centre of the ovary as an upgrowth from ovary base which bears ovule.Ex. Primrose |
| BASAL | Bi or multicarpellary & unilocular ovary | Few or one born on the base of ovary Ex.Marigold |
| SUPERFICIAL | multicarpellary & multilocular ovary | Ovule born on placentae which develop all around the inner surface of the partition wall. Ex Nymphaea |
