CHAP. CVII.

PLATANA'cEjE. pi.a/tanus.

2045

from the ground, or about I ft. 10 in. in diameter; which gives nine lines anda half, or more than three quarters of an inch, of increase annually.

Geography. The American plane is found over an immense tract of landin North America, comprising the Atlantic and western states, and extendingbeyond the Mississippi. “ The nature of the button-wood,” says Michaux,“ confines it to moist and cool grounds, where the soil is loose, deep, and fertile;the luxuriance of its vegetation depending on a combination of these circum-stances. It is never found upon dry lands of an irregular surface, amongwhite and red oaks and walnuts ; it is also more rare in the mountainous tractof the Alleghanies than in the flat country. It is remarked, in that part ofVirginia which lies upon the road from Baltimore to Petersburg, that, thoughthe button-wood is abundant in the swamps, its growth is stunted; and that itstrunk does not, in general, exceed 8 in. or 10 in. in diameter. Farther south, inthe lower parts of the Carolinas and of Georgia, it is not abundant even on thesides of the rivers; and is not seen in the branch swamps, already mentioned,which intersect the pine barrens, and which are principally covered with thesmall magnolia (Magnolia glauca), the red bay (Laurus caroliniensis), theloblolly bay (Gordonia Lasianthus), the red maple (A'cer rubrum), &c. Thereason that the button-wood is not found in these small marshes is, perhaps,that the layer of vegetable mould, which is black and always miry, is not suf-ficiently thick and substantial to support its growth; and that the heat, in thispart of the southern states, is excessive. The button-wood is in no part ofNorth America more abundant and more vigorous than along the great riversof Pennsylvania and of Virginia; though in the more fertile valleys of thewest its vegetation is, perhaps, still more luxuriant; especially on the banksof the Ohio, and of the rivers which empty into it. The bottoms which arewatered by these rivers are covered with dark forests, composed of trees ofan extraordinary size. The soil is very deep, loose, of a brown colour, andunctuous to the touch : it appears to have been formed by the slime depositedin the course of ages, at the annual overflowing of the rivers. The leaves,which every autumn form a thick layer upon the surface, and the old trees,that fall by the weight of years, and crumble into vegetable mould, give tothis soil, already so fertile, a degree of fecundity which is without example inEurope, and which is manifested by prodigies of vegetation. The margin ofthe great rivers of the West is occupied by the willow, after which comes thewhite maple (A'cer eriocarpum), and next the button-wood; but this arrange-ment is not uniformly observed; and the maple alone, or, as it more fre-quently happens, mingled with the button-wood, sometimes grows upon thebrink. Among the trees which compose these forests, the three species men-tioned are least liable to injury from the continued presence of water; and, bytheir position, they are exposed to have their bases every year inundated bythe swelling of the rivers. In these situations, the button-wood is constantlyfound to be the loftiest and largest tree of the United States.” (North Amer.Syl., ii. p. 58.)

History. In the Atlantic states, this tree is commonly known by the nameof button-wood; and sometimes, in Virginia, by that of water beech. On thebanks of the Ohio, and in the states of Kentucky and Tennessee, it is mostfrequently called sycamore, and by some persons plane, tree. The French ofCanada and of Upper Louisiana give it the name of the cotton tree. Thefirst of these denominations appears to be the most widely diffused, and, infact, to be that by which the tree is most generally known in America. Thename cotton tree alludes to the thick down which covers the under surfaceof the leaves when they first expand, and which becomes gradually detachedfrom them in the course of the summer. In some parts of the United States,where the tree is very abundant, the inhabitants, according to Michaux, regardit with dread, as they think this down, detached and floating in the air, has atendency to produce irritation of the lungs, and, finally, consumption. TheAmerican plane was one of the trees discovered and figured by Catesby inhis Natural History of Carolina (i. t. 56.); and it was introduced about 1630,