34 HOUGH'S AMERICAN WOODS. 



ORDER BETULACE AE : BIRCH FAMILY. 



Leaves simple, alternate, straight- veined and furnished with stipules which fall 

 away early. Flowers mostly naked, monoecious, both kinds in catkins, 2 or 3 

 together under a 3-lobed bract or scale. Sterile flowers with distinct stamens and 

 2-celled anthers. Fertile flowers with two thread-like stigmas, and a 2-celled 

 ovary, each cell containing 2 pendulous ovules, becoming by abortion in Fruit, a 

 small, 1-celled, 1-seeded nutlet, often with membranous wings ; seed anatropous, 

 albumenless, with flattish, oblong cotyledons which become foliaceous in germina- 

 tion. 



Trees or shrubs, with bark which separates more or less easily into thin layers 



GENUS BETULA, TOURNEFORT. 



Leaves ovate, serrate; these, with the twigs, especially the latter, often spicy 

 aromatic. Flowers appearing in early spring with or before the leaves. Sterile 

 flowers in long, drooping, cylindrical, both terminal and lateral, yellow catkins, 

 appearing in summer and remaining dormant during the following winter to 

 open and perform their function early the next season; bracts 3-lobed. shield- 

 shaped, and beneath each are 2 bractlets and 3 flowers with calyx represented by 

 a mere scale, which bears the 4 short stamens, each with a single-celled anther. 

 Fertile flowers in cylindrical or oblong catkins with 3-lobed scales, and beneath 

 each scale are 2-3 naked pistils without bractlets or calyx. Fruit a small, 

 broadly- winged, scale-like nutlet or samara. 



Trees and shrubs with outer bark horizontally fibrous and usually separable in 

 sheets, that of the branchlets dotted, inner bark more or less aromatic and of 

 pleasant flavor. (The ancient Latin name, from Celtic Betu, birch.) 



236. BETULA OCCIDENTALIS, HOOK. 

 WESTERN BIRCH. PUGET SOUND BIRCH. 



Ger., Westliche BirTce Fr., Bouleau occidental; Sp., Abeclul 



occidental. 



SPECIFIC CHARACTERS: Leaves ovate, 3-4 in. long, acute, rounded (rarely 

 cuneate) at base, irregularly and usually doubly serrate, at first pale green dotted 

 with resin glands and villous along the midribs, at maturity firm, pitted with the 

 scars of the fallen resin glands, dark green above, paler and puberulous along 

 the veins beneath; petioles about 3-4 in. long, glandular, grooved, pubescent; 

 stipules oblong-ovate, glandular- viscid, about -| in. long; branchlets pubescent 

 and glandular at first, the second season glabrous, orange-brown marked with 

 pale lenticels. Flowers open in May, the staminate catkins 3-4 in. in length, and 

 the pistillate -f in. Fruit oblong-cylindrical pendulous strobiles, 1| to 

 1| in. in length and in. or less in thickness, borne on stout peduncles about 

 | in. long, the scales much longer than broad, puberulous outside with elongated 

 terminal lobe and spreading lateral lobes, gradually narrowing to base; nutlet 

 ovoid, about -$ in. long and wings somewhat wider. 



The Western Bircli attains the height of upwards of 100 ft. (30 in.) 

 with trunk 3 or 4 ft. (1 in.) in diameter, vested in a thin lustrous 

 orange-brown and pearl-colored bark, marked with large raised 

 lenticels and peeling off in papery layers, and strips transversely 

 around the trunk. 



HABITAT. Southwestern British Columbia, Yancouver Island and 

 northwestern Washington, growing in moist alluvial bottom-lands and 

 along the banks of streams. 



