River Birch 



255 



brown. The leaves are ovate, thin, sharply ir- 

 regularly toothed, pointed, 5 cm. long or less, 

 bluntly to narrowly wedge-shaped at the base, 

 long-hairy when young, when mature rather dark 

 green, smooth and somewhat shining on the 

 upper surface, pale green and sparingly hairy on 

 the under side; the very slender leaf-stalks are 

 smooth or nearly so, i to 2 cm. long, the thin ovate 

 stipules about 5 mm. long. The flowers open in 

 May. The staminate catkins are 6 to 8 cm. long, 

 the ripe pistillate catkins are narrowly cylindric, 3 

 to 5 cm. long, about 8 mm. thick, bome on stalks 

 about 7 nun. long; their scales are about 6 mm. 

 long, longer than wide, 3-lobed at the top, finely 

 hairy and hairy-fringed, the lateral lobes spread- 

 ing, roimded, a Uttle shorter than the narrower 

 middle one, the stalk-like part below the lobes 

 wedge-shaped; the nut is 1.5 to 2 mm. long, obo- 

 vate to oblong and wider than its wings. 



Fig. 212. — Piper's Birch. 



II. RIVER BIRCH — Betula nigra Linnaeus 



The River birch, or Red birch, grows naturally in moist soil in river valleys 

 and along the borders of ponds and swamps, from southern New Hampshire and 



Massachusetts to Florida, extending westward 

 to Illinois, Iowa, Minnesota, Nebraska, Kansas, 

 and Texas, thus having a more southern range 

 than any other American species. It reaches 

 a maximum height of about 30 meters and a 

 trunk diameter of 1.5 to 2 meters. 



The bark is reddish brown and thick; near 

 the bases of old trees it is ridged and scaly, 

 but higher up, and on young trees, it is red- 

 brown to green-brown or gray, and peels off 

 freely in thin layers. The young twigs are 

 greenish and densely velvety, becoming smooth 

 and red-brown. The buds are pointed, hairy, 

 and about 6 mm. long. The leaves are rhom- 

 bic-ovate, irregularly and often doubly toothed 

 or somewhat lobed, 3 to 8 cm. long, pointed, 

 rather firm in texture and tough, the base varying from narrowly to broadly 

 wedge-shaped or even truncate; they are long-hairy when young, when mature 

 dark green, smooth, and shining on the upper side, pale and velvety or sometimes 



Fig. 213. — River Birch. 



