The Orders of the great natural 19th Class, Syngenesia, are marked by the united or separated, barren, fertile, or abortive, nature of the florets.
1. Polygamia æqualis. Florets all perfect or united, that is, each furnished with perfect Stamens, a Pistil, and one Seed.
2. Polygamia superflua. Florets of the disk with Stamens and Pistil; those of the radius with Pistil only, but each, of both kinds, forming perfect Seed.
3. Polygamia frustranea. Florets of the disk as in the last; those of the radius with merely an abortive Pistil, or with not even the rudiments of any. This is a bad Order, for reasons hereafter to be explained.
4. Polygamia necessaria. Florets of the disk with Stamens only, those of the radius with Pistils only.
5. Polygamia segregata. Several flowers, either simple or compound, but with united anthers, and with a proper calyx, included in one common calyx.
