=2.= =Betula populifòlia= Marshall. Gray or White Birch. Plate 33. A small tree; bark a chalky-white, not separating into thin layers, inner bark orange, on the trunks of old trees nearly black; shoots at first covered with numerous glands, becoming smooth and yellowish or reddish-brown; leaves generally long-deltoid, average blades 3-6 cm. long, usually long taper-pointed, truncate or nearly so at the base, irregularly double-serrate, slightly pubescent on the veins when young, soon becoming glabrous; fertile catkins 1.5-3 cm. long and about 7 mm. in diameter; bracts of eastern trees differ from those of Indiana trees which are about 3-4 mm. long, lobed to about 1/3 of the distance from the apex, lateral lobes the largest and strongly divaricate, puberulent on the back; seed strongly notched at the apex; nut slightly obovoid; wings much broader than the nut. =Distribution.=--Nova Scotia west to southern Ontario and south to Delaware and Pennsylvania. In Indiana it has been reported from Lake, Laporte, Porter, St. Joseph and Tippecanoe Counties. There may be some doubt about the Tippecanoe record, since many of the older records were made from cultivated trees. The numbers of the species in Indiana were always limited. It is not able to meet changed conditions and it has already almost disappeared from our area. I was told that formerly this species was found all about a lake in Laporte County, but it has all died out. Its appearance in Indiana is peculiar since it is not found west of us, or north in Michigan or east in Ohio. This small group of trees near Lake Michigan is three or four hundred miles from the nearest of their kind. =Remarks.=--This species is called white and gray birch. The largest tree seen in Indiana was about 2 dm. in diameter and 13 m. high. [Illustration: Plate 33. BETULA POPULIFOLIA Marshall. White or Gray Birch. (× 1/2.)] [Illustration: Plate 34. BETULA PAPYRIFERA Marshall. Paper or Canoe Birch. (× 1/2.)] =3.= =Betula papyrífera= Marshall. Paper or Canoe Birch. Plate 34. Rather a small tree; bark thin, creamy white; chalky, dark near the base on old trees, separating in thin papery layers; shoots green, glandular and hairy, becoming glabrous and reddish-brown; leaves ovate or rhombic-ovate, acute to long taper-pointed, truncate, rounded or wedge-shape at the base, average blades 5-8 cm. long, usually irregularly double-serrate, hairy at first, becoming glabrous above or nearly so, remaining more or less pubescent below, especially on the veins and with tufts of hairs in the axils of the veins, minutely glandular on both surfaces, sometimes with only a few glands on the midribs above; fertile catkins 2-4 cm. long and about 6-9 mm. wide, bracts about 4 mm. long, pubescent on both faces, lobed to about one-third the distance from the apex, the lateral lobes the largest, divaricate or slightly recurved; seed deeply notched at apex, nut oval, pubescent at the apex, wings as broad as, or broader than the nut.