=1.= =Populus álba= Linnæus. Silver-leaf Poplar. Plate 15. Short-trunked trees with a round top, up to a meter or more in diameter; bark on young trees smooth, greenish-white or gray, becoming furrowed on old trees, gray or dark brown; shoots white tomentose, becoming smooth in age; leaves ovate or triangular, 3-5 lobed or irregularly toothed, hairy on both surfaces on expanding, becoming dark green and glabrous above, remaining white tomentose beneath; stamens about 8; wood light, soft and weak. =Distribution.=--Introduced from Europe and escaped in all parts of the State. =Remarks.=--This tree has long been under cultivation, and several horticultural forms have been introduced. It is falling into disuse on account of its habit of sending up root shoots. It adapts itself to all kinds of soil, grows rapidly, transplants easily, stands pruning well and has few insect or fungous enemies. [Illustration: Plate 15. POPULUS ALBA Linnæus. Silver-leaf Poplar. (× 1/2.)] =2.= =Populus heterophylla= Linnæus. Swamp Cottonwood. Swamp Poplar. Plate 16. Tall trees up to 5-8 dm. in diameter; bark of old trees very thick, broken into long ridges which are separated by deep furrows, reddish-brown but generally weathered to ash-color; shoots densely woolly at first, becoming glabrous before the second season; leaves broadly-ovate with petioles 2-10 cm. long, more or less woolly on both surfaces on unfolding, becoming glabrous above and remaining woolly beneath, at least on the larger veins, rarely becoming entirely glabrous, usually cordate at the base, blunt at apex, margins rather regularly crenate-serrate; flowers in April; capsules ripening in June, about 6 mm. in diameter, on stalks 5-10 mm. long; wood same as the next species. =Distribution.=--Along the Atlantic Coast from Connecticut to Florida and along the Gulf to Louisiana, and northward along the Mississippi Valley to Michigan. It is found in many parts of Indiana. In the northern counties it is found in "gumbo" soils in swamps. It is a common tree in the river swamps of the lower Wabash Valley where it reaches its greatest size. There are no records for the extreme southeastern part of the State, although it has been found in swamps in Harrison and Clark Counties and is found in many counties of Ohio. =Remarks.=--The pith of the shoots of this species is orange which easily distinguishes it from all other species of the genus which have a white pith. This species in all of its range is closely associated with the common cottonwood, and millmen make no distinction in the price or qualities of the timber.