Identifying American Basswood Trees

Trees in the Linden Family (Tiliaceae)

American basswood tree growing in front of a brick building on a sunny day.

Virens (Latin for greening)/Flickr/CC BY 2.0

Tilia is a genus within the Linden family (Tiliacea). This family contains about 30 species of trees that are native throughout most of temperate Northern Hemisphere. The greatest species diversity of the lindens is found in Asia. It exists only scattered in pockets throughout Europe and eastern North America. The trees are sometimes called "lime" in Britain and "linden" in parts of Europe and North America.

The most common name for the tree in North America is American basswood (Tilia americana), but there are several varieties with separate names. White basswood (var. heterophylla) is found from Missouri to Alabama. Carolina basswood (var. caroliniana) is found from Oklahoma to North Carolina and south to Florida.

The fast-growing American basswood is among the largest trees of eastern and central North America. The tree will often support several trunks off its base, will prolifically sprout from stumps, and is a great seeder. It is an important timber tree in the Great Lakes states. Tilia americana is the northernmost basswood species.

Basswood flowers produce an abundance of nectar from which choice honey is made. In fact, in some parts of its range basswood is known as the bee-tree, and can even be identified by the honey bee traffic. 

Basswood Tree Identification

Basswood's asymmetrical and lopsided heart-shaped leaf is the largest of all broadleaf trees, nearly as wide as it is long at between 5 and 8 inches. The rich green upper side of the leaf is in contrast to the underleaf's paler green to almost-white color.

The basswood's small greenish flowers are uniquely attached and hanging under a pale, leaflike bract. The resulting seeds are in a hard, dry, hairy, nutlike fruit, which is quite visible during the fruiting season. Also, take a close look at the twigs and you will see them zigzag between oval buds with one or two bud scales.

This tree should not be confused with the non-native urban basswood called little leaf linden or Tilia cordata. The leaf of the linden is much smaller than basswood and typically, it is a much smaller tree.

Characteristics

  • Leaves: Alternate, broadly ovate, coarsely saw-toothed, notched at the base.
  • Bark: Dark gray and smooth.
  • Fruit: Elliptical nut-like, hard seed.