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23. . Stamens and Pistils separate in some flowers, united in others, either on the same plant, or on two or three different ones.

This Class is natural only when the several flowers have a different structure, as those of Atriplex; but in this genus the Pistil of the united flower scarcely produces seed. If, with Linnaeus, we admit into Polygamia every plant on which some separated barren or fertile flowers may be found among the united ones, while all agree in general structure, the Class will be overwhelmed, especially with Indian trees. I have therefore proposed that regard should be had to their general structure, which removes all such inconvenience, and renders the Class much more natural.

24. . Stamens and Pistils either not well ascertained, or not to be numbered with any certainty, insomuch that the plants cannot be referred to any of the foregoing classes. Of this Ferns, Lichens, Sea-weeds and Mushrooms are examples.