Kansas Wildflowers and Grasses

RIVER BIRCH

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Betula nigra L.

Clay County, Kansas

Height: To 72 feet

Family: Betulaceae - Birch Family

Flowering Period: April

Trunks:

Erect; bark grayish brown, yellowish white, or reddish white, exfoliating in thin, papery flakes or sheets; wood tan, hard.

Twigs:

Reddish brown to grayish brown, flexible, glabrous or sparsely pubescent, often with scattered resinous glands; leaf scars triangular; buds reddish gray, ovoid, .2 to .25 inch, apex acute, scales pubescent.

Leaves:

Deciduous, alternate, simple; petiole .3 to .6 inch; blade rhombic-ovate to narrowly deltate, 1.6 to 3.6 inches long, 1.4 to 2.4 inches wide, base cuneate to truncate, margins coarsely 2-serrate, apex acute to acuminate, surfaces abaxially green, pubescent to velutinous, adaxially dark green, glabrous or sparsely pubescent.

Flowers:

Inflorescences formed in previous season and exposed in winter, catkins; staminate: mostly terminal, 1-3, pendent, 2.8 to 3.6 inches long, .2 to .3 inch wide, many-flowered; pistillate: proximal to staminate, 1, erect, .8 to 1.2 inch long, .8 to 1.2 inch long, .2 to .3 inch wide, many-flowered, becoming cone-like but not woody in fruit, conic to globose, 1 to 2.4 inch long, .4 to 1 inch wide; peduncles .4 to 1.5 inch; unisexual, more or less radially symmetric; staminate: bracteate, each bract with 3 flowers; sepals 2-4, distinct, ovate, minute; petals absent; stamens 2; pistillate: bracteate, each bract with 3 flowers; perianth absent; pistil 1; styles 2; stigmas 2.

Fruit:

May and June; samaras, reddish brown, broadly ovate, .1 to .14 long, .2 inch wide, glabrous, wings 2, broad; seed 1.

Habitat:

Floodplain forests and woodlands, stream banks, swamps.

Distribution:

Southeast corner of Kansas; also planted widespread.

Origin:

Native

Comments:

Betula nigra is a fast-growing, graceful tree, often with leaning multiple trunks and slightly arched branches. It is a popular shade tree in eastern Kansas. When in fruit, it attracts large numbers of seed-eating birds—especially finches, chickadees, titmice, sparrows, and cardinals.

River birch catkins