There is a vestigial non-functional perigynous disc and nectar is secreted by glandular trichomes distributed along the internal surface of the corolla. |
Also, instead of a perigynous disk, there are usually little scales on the receptacle, one behind each carpel. |
These latter were classified according to whether the parts of the flower were hypogenous, perigynous, or epigynous. |
Flower of a buckthorn showing a conspicuous perigynous disk. |