It will be readily understood therefore that the following is a pretty full list of the plants growing naturally within the state of Illinois. Further researches will undoubtedly reveal some new treasures, but compared with the whole [number] their number [must] will be small.
A glance at the geographical position of Illinois with a knowledge of her principal topographical features will prepare us to look for a rich Flora. Bordering on the Great Lakes; bounded on her whole western side by the Great Mississippi river; with the valley of the wa[u]bash on the East, and of the Ohio on the south; she is nearly surrounded by water. The southern extreme of the state lies in latitude 37 degrees or nearly as far south as the lower part of Kentucky and Virginia, and has an elevation of only 275 feet at the low water of Cairo above the ocean level. Here are found quite a number of plants that do not extend into the central mid northern portions of the state. There are distinguished in the following catalogue by the letter S. The north line of the state is in Latitude 42 degrees 30' and partakes in a considerable degree of
the characters of the south part of the adjoining state of Wisconsin. The plants in the following list found here and which do not extend to the central and southern parts of the state are distinguished by the letter -N.
The central portions of the state lie on a nearly uniform plain whose average elevation is considerably below the level of Lake Michigan (578 feet above the ocean) and constitute the great prairie districts. These are rapidly being subdued, and converted into "improved lands," from which almost every trace of the original vegetation is destroyed. The time will soon come when many of the species here enumerated will exist no longer in Illinois. Already the number of "introduced" species is very considerable.
Mere catalogues of the plants growing in any locality might be supposed to possess but little value, a supposition which would be far from the truth. The intelligent farmer looks at once to the native vegetation as a sure indication of the value of new lands. The kinds of timber growing in a given locality will decide the qualities of the soil for agricultural purposes. Such lists are useful in a scientific point of view, as showing the geographical limits of species, and which are diffused generally, or confined to limited districts. Many very useful as well as highly interesting results are obtained by comparing different catalogues, and by a study of the statistic[le]s of the different Floras.
The Farmer will be interested to find how few of the plants he so assiduously cultivates are indigenous to the soil. The Physician will see which of the plants having medicinal value may be gathered in his neighborhood; and may thus in cases of sudden emergency, when no time is allowed to send to a distant apothecary, be enabled to effect important cures. The cabinet maker, the wheelwright, and all other workers in wood will find what materials are at hand to answer their purposes. The horticulturalist
will look over the "dry list" with deep interest to find what flowers and shrubs may be gathered at Rome, and thus save the expense and trouble of purchasing and transporting from the east (perhaps covered with noxious insects) the very plants he could have found near his door.
It will be seen by the enumeration, that there are over seventy species in Illinois that attain the height and dignity of forest trees. 12 or 13 oaks. The rich bottom lands along the margins of the Mississippi, the Ohio, and the Wabash, afford specimens of the noblest and most gigantic trees of the Great Valley the West of It was here that Michaux wandered at a time when but few white men had penetrated so far into the wilderness. IT was here that he became so deeply impressed with the grandeur and magnificence of the forests of the New World. "The difficulties, privations, and dangers, to which he was exposed, at that early day, in there unsettled wilds may be easily imagined but we can as readily conceive that there were [all] more than balanced in his mind by the delights which he experienced in traversing a hitherto untrodden region, though which in reference to the lights of science and the labors of civilization, may truly be said
He bent his way where twilight reigns sublime O'er forests silent since the birth of time' " * The "Sylvia Americana" of his son remains to this day the only standard work on the Forest Trees of the United States.
*Dr. C.W. Short on the Progress of Western Botany p. 7