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.
Distribution.—Alaska to Labrador, south to New York, northern Indiana, Colorado and Washington. In Indiana it has been reported from Lake, Laporte, Marshall and St. Joseph Counties. It has not been found as a native in Ohio. This species is another example of a northern form finding its southern limit near Lake Michigan.
Remarks.—This species in other parts of the country is known as white, paper and canoe birch. I have not seen specimens more than 2 dm. in diameter in Indiana.
4. Betula nìgra Linnæus. Black or Red Birch. [Plate 35.] A medium sized tree; bark on young trees peeling off transversely in thin reddish-brown strips which roll back and usually persist for several years, bark of older trees dark brown, furrowed and separating into short plates or peeling off in strips; young twigs hairy, becoming glabrous and reddish at the end of the season; leaves rhombic-ovate, acute, short and broadly wedge-shaped at the base, blades of ordinary leaves 4-8 cm. long, irregularly toothed, glabrous above and pubescent beneath, rarely entirely glabrous; fertile catkins generally 2-3 cm. long, and usually slightly less than 1 cm. wide; bracts 6-10 mm. long, pubescent, ciliate, lobed to near the middle, the lobes about equal; nuts broadly ovate, broader than its wings, pubescent at the apex; wood light, strong, close-grained, heart wood light brown.
Distribution.—Massachusetts west to Minnesota and south to Florida and Texas. In Indiana it is found more or less frequent in the counties bordering the Kankakee River, and as far east as St. Joseph, Marshall and Miami Counties. Along the Kankakee River it is frequently a tree of 6-8 dm. in diameter. This species has not been found in Michigan, northeastern Indiana or northern Ohio. It has never been noted near Lake Michigan, and the nearest point is Cedar Lake in Lake County about 20 miles south of the Lake. It is more or less frequent along certain streams throughout the southwestern part of the State. It is found as far north as Putnam and Marion Counties and eastward as far as Bartholomew, Scott and Clark Counties. There are no records for this species for eastern Indiana or western Ohio. About Hovey Lake in Posey County it reaches its greatest size, where trees up to 8 dm. in diameter and 30 m. high are to be found. In the "flats" in certain parts of Jackson and Scott Counties it becomes a common tree, associated with pin oak and sweet gum.