p.17

From these tables it will be seen that there are in Illinois one hundred and sixty six native species of Compositae, or compound flowering plants; one hundred and two of Graminae or true grasses; ninety seven of Cyperaceae or sedge grasses; forty nine of Leguminoseae or plants of the pea family. [growing naturally of Illinois]. The whole number of species (1052) is [just] almost exactly half the number found to be natives of the northern United States; and the same remark holds [very nearly] good when we compare the numbers of each of the great classes of plants. It will be seen too that there are in Illinois more true grasses than Cyperaceae, while in the whole northern United States the reverse is true; and that [The Flora of Illinois exhibits this further peculiarity, that] the species are more concentrated into the larger orders. [than is usual in any Flora in the same climat and latitude]. in the whole northern states. The large orders Compositeae, Graminae, Leguminae, [Scropheae?], [Rosacea?], Labiaeae, and Umbilifeae in Illinois contains respectively more than half the species of the northern United States, while only Cyperaceae and Rosacea, among the larger orders contain less.

Of 132 natural orders found native in the northern U.S. 111 are represented in Illinois.