Trees and Shrubs of the Eloise Butler Wildflower Garden

Yellow Birch is a large native aromatic deciduous tree with a straight trunk and broad rounded crown of drooping branches growing 70 to 100 feet high. The crown will be irregularly narrow in dense woods.

The largest known Yellow Birch in Minnesota is in Itasca County, measuring 76 feet high, 63 foot crown spread, 150 inches in circumference and scoring 241.75 points. The National Champion is in Kennebec County ME, measuring 95 feet high, 80 foot crown spread, 242 inches in circumference and scoring 357 points.

Bark is a smooth shiny reddish-brown that separates into papery curly strips and with age becomes tan to golden-yellowish or silver gray with expanded lenticels, fissures and scaly plates. The golden yellow of a typical mature tree is how the common name came about.

Twigs are greenish-brown to reddish-brown, slender, with hair when young; smooth and brown later, with scattered light colored lenticels, and usually have small glands. The glands and the inner pith give off a wintergreen odor and taste when crushed. Buds are ovoid, sharp pointed, reddish-brown with a fringe of hair on the scale margins.

Leaves are alternate, simple, elliptical, 4 to 6 inches long with a pointed tip, rounded to heart-shape base and a sharp double-toothed margin, 9 to 11 veins per side, dark dull green above, light yellow green below, hairy when young. Leaves often have resinous glands along the vein which also give off the wintergreen odor when crushed. There are small stipules at the base of the leaf stalk. Leaves usually occur on short spur shoots of the twig, 2 per shoot. Fall color is a bright yellow.

Flowers: The tree is monoecious, that is with separate male and female flowers. Male flowers (staminate) occur in a cluster of 3 to 6 reddish-green catkins, that appear near the ends of twigs in the fall and then in the Spring elongate forming hanging clusters up to 3 - 4 inches long while taking on a yellow-purple color. The individual flowers are only 1/8 inch long, are yellowish with 2 stamens, a 4-lobed calyx and are in groups of 3 on the catkin and somewhat obscured by small bracts. Female flowers (pistillate) appear with the leaves and are reddish-green upright catkins, about 3/4 to 1-1/4 inches long at maturity, back of the tip on the same twigs. Each flower has an ovary, a pair of styles but no calyx or petals and occur in groups of 3 on the catkin and are also obscured by bracts. Catkins are also referred to as 'aments'.

Fruit: Pollination is by wind. Pistillate flowers mature to a short-stalked upright cylindrical non-woody cone-like structure, 3/4 to 1-1/4 inches long, brownish in color with many 3-lobed hairy scales, each scale containing a 2-winged nutlet, the wings narrower than the nutlet, which mature in the fall and disperse by wind and water in the winter. These cone-like structures will usually remain on the twig after seed release. Seeds are not produced on young trees and once production starts crops are heavy once every 10 years and much lighter on intervening years.

Habitat: Yellow Birch grows in many environments from moist marsh areas to uplands. It has adapted to landscape plantings and grows well if adequate moisture is provided. Full sun is best- it tolerates some shade but not deep shade. It can be a long-lived tree, unlike the Paper Birch. It does not spread from its root crown, but will re-sprout from a stump although those sprouts are usually short lived. It's root system is broad and shallow. The plant will hybridize with Paper Birch but unlike Paper Birch it is a dominant species.

Names: The genus, Betula, is the Latin word for the birch tree. The species, alleghaniensis, refers to the Allegheny Mountains where the tree is prevalent. In the 19th Century the species was sometimes named B. lutea, from the Latin lutum for 'yellow'. The name 'birch' itself is derived from an old Teutonic word. The author name for the plant classification from 1904 - ‘Britton’ is for Nathaniel Lord Britton (1859-1934) American botanist and taxonomist, co-founder of the New York Botanical Garden, signatory of the American Code of Botanical Nomenclature and co-author with Addison Brown of Illustrated Flora of the Northern United States, Canada, and the British Possessions in 1896.

Comparisons: The Yellow Birch has some similar characteristics to Sweet Birch, B. lenta - leaves that have a rounded to heart shaped base and 8+ pairs of lateral veins on the leaf. But Sweet Birch has bark that is a reddish-brown to black and the scales of its cones do not have hair on the margins. Other birches have leaves not usually rounded or heart-shaped at the base and have fewer than 8 lateral veins, and the scales of the cones fall away quickly rather than persist into winter. See leaf comparison photo below.