Class XXI. Order VIIL 231 



the maple. Four of the trees yielded in one day nine quarts of 

 sap, which produced one and a quarter pounds of sugar. 



265. BETULA. 

 BETULA POPULIFOHA, Ait. Common white Birch. 



Leaves extensively acuminate, unequally ser- 

 rate, glabrous. Jllich.f. 



The name of white birch is indiscriminately applied to this 

 species, and to Betula papyracea, a species common in the Dis- 

 trict of Maine, and which furnishes a considerable part of the 

 eastern wood consumed in this town. The present species is 

 common here in swamps, and multiplies very fast in moist 

 lands that are not properly cleared. Like the paper birch, its 

 trunk is covered with a white, smooth, outer bark, separable in- 

 to thin layers, and very inflammable. Its young twigs are flex- 

 ible, of a dark brown, spotted with white. The leaves arc 

 heart-shaped, tapering to a long point, glutinous, smooth on 

 both sides. The flowers, both barren and fertile, are in lon^-, 

 pendulous aments. The wood is white, -soft, and very perisha- 

 ble, decaying sooner than the bark. 



BETULA LENTA. L. Slack Birch. Mahogany Birch. 



Leaves heart-ovate, acutely serrate, acuminate, 

 glabrous. Mich. f. 



Syn. BEfuLA CARPIXIFOLIA. Mii/i. 



This fine tree, sometimes also denominated Sweet birch, 

 and Cherry birch, is well known for its fragrant and aromatic 

 bark. Its young twigs arc dark coloured, and spotted with 

 white. Its leaves are smooth, ovate, heart-shaped at base, end- 

 ing in a long point, with very acute, double serratures at tlu: 

 edge, and distinct, parallel veins underneath. The barren 

 aments are pendulous, the fertile ones straight. 



The wood of the black birch possesses many valuable qual- 

 ities. It is compact, smooth, of a reddish colour, very strong-. 



