Murray's birch

Trees , to 15 m; trunks usually several. Bark of mature trunk and branches dark red to reddish brown, smooth, close; lenticels pale, conspicuous, horizontally expanded. Twigs with taste and odor of wintergreen when crushed, glabrous to sparsely pubescent, covered with small resinous glands. Leaf blade ovate with 7--10 pairs of lateral veins, 5--11 × 3--6 cm, base cuneate, margins sharply and obscurely doubly serrate, apex acute or only slightly acuminate; surfaces abaxially sparsely pubescent to glabrous. Infructescences erect, ovoid, 2--4 × 1.5--3 cm, remaining intact for a period after release of fruits in late fall; scales sparsely pubescent to glabrous, lobes ascending, branching at middle, slightly unequal in length. Samaras with wings narrower than body, broadest near summit, not extended beyond body apically. 2 n = 112.

Flowering late spring. Wet, swampy forests containing Betula pumila ; of conservation concern; 0--300 m; Mich.

Betula murrayana is an octoploid derivative of Betula × purpusii (= B . alleghaniensis Britton × B . pumila Linnaeus) (B. V. Barnes and B. P. Dancik 1985). It is intermediate between B . alleghaniensis and B . pumila in most vegetative features, but in characters such as leaf size, it approaches B . alleghaniensis .