Flower:

Male and female flowers are borne separately on the same tree (monoecious) in dangling clusters called catkins. Male catkins are stalkless, ¾ to 2 inches long arising singly from lateral buds on one-year-old branchlets, the flowers each with a yellow-green bract and red stamens.

Female catkins are 1/3 to 1¼ inch long at the tip of new branchlets, the flowers in pairs, each with a hairy, leaf-like bract and red styles. The bracts eventually grow to 1 inch or more long, becoming 3-lobed with smooth or irregularly toothed edges.

Leaves and stems:

Leaves are simple and alternate, the blade egg-shaped to elliptic, 2½ to 5 inches long, 1 to 2 inches wide, tapered to a pointed tip, the base rounded to somewhat heart-shaped, edges coarsely and sharply double-toothed. Upper surface is dark green with prominent veins evenly spaced along the midrib, the surface smooth to sparsely hairy, the lower surface lighter green, hairy, especially along the veins, and gland-dotted. Fall color is yellow-orange to red.

New branchlets are hairy, one year old twigs are slender, the reddish brown bark almost shiny with scattered white lenticils (pores).

Older bark is light gray and smooth, the wood underneath rippled, sinew-like. Trunks of large shrub-size trees are typically 4 to 5 inches diameter though a large specimen (rare in Minnesota) may reach a foot in diameter. It is often clonal from root suckers.

Fruit:

The fruiting catkin is up to 2¾ inches long, the fruit a small, greenish, hairy nutlet attached to the large, leafy, three lobed bract.

Notes:

The name Blue Beech is a misnomer, as it is in the Birch family and unrelated to Beech (Fagus spp.) trees. While distributed throughout much of Minnesota's eastern deciduous forests, Blue Beech is by no means frequently encountered or, perhaps more so, not readily recognized. A understory species of moist lowland forests, it is a small-statured tree whose crown is easily lost in the lower canopy, and its tendency for multiple stems, even small colonies from root suckers, can give it a shrub-like appearance. Its leaves can be confused with both Ironwood (Ostrya virginiana) (which also has a similar growth habit) and Elms (Ulmus spp.), but the under surface of its leaves are dotted with tiny dark brown glands and its smooth, gray muscle sinew-like texture trumps all other characteristics. Blue beech makes an excellent small shade garden species.