Posted by Mike Adamovic on the Native Plants of the Northeast’s Facebook page:

Basswood is one of the finest canopy trees to be found in our forests. Every aspect of this species is commonly understood to be attractive—its large heart-shaped leaves, finely furrowed bark, pendulous branches that cast a deep shade, and, for a couple of weeks in early summer, its cream-colored flowers, which exude a scent as strong as perfume and often give away the tree’s presence before one lays eyes on it. These attributes have led many parks and large estates to plant this most regal of trees.

Basswood thrives in rich, mesic soils. It performs best in full sun to light shade. It has an extensive range—from Maine to the eastern edge of North Dakota, south to Arkansas, and east to North Carolina. It generally isn’t the most common of trees in many parts of the Northeast, but it can be locally abundant in the western fringes of our region.

The name basswood comes from the word “bast”—tough fibers in the bark useful for making a variety of items. Basswood has some of the longest and strongest fibers of any of our native trees. Native Americans collected the bark in the spring and used it to create flexible handles, or with further processing, cordage. Another commonly used name for this species is American linden.

Trees usually range in height from 50-100’, though on rare occasions they can reach up to 120.’ In open areas, mature trees have a bell-shaped form. It is one of the best trees to plant if you require a shade tree. This is due to basswood’s narrow form, as well as the arrangement of branches and its broad leaves the size of human hands, which effectively capture more light than the sinuous leaves of oaks.

Individual flowers around a half inch in diameter are borne on drooping cymes 1-3” across. Each inflorescence typically contains around ten flowers, though it can contain as few as five to as many as twenty. As mentioned earlier, the flowers are incredibly potent, having a scent somewhat between a sweet floral perfume and strong household cleaners. It can be overpowering if you’re near a tree or the wind happens to catch and drive the fragrance in your direction.

Honeybees visiting basswood flowers produce a paler honey with a lighter flavor that’s highly prized. In terms of our native insects, when this tree is in flower, pollinators will be redirected, forsaking other plants for the sumptuous blooms of basswood that are rich in nectar. Bumblebees, halictid bees, flies, moths, and other insects feverishly swarm the trees.

There have been over 150 species of Lepidoptera recorded using basswood as a larval host plant. A few which use it primarily or solely as a host plant include the basswood leafroller (Pantographa limata), linden prominent (Ellida caniplaga), double-lined prominent (Lochmaeus bilineata), linden looper (Erannis tiliaria), and four-horned sphinx (Ceratomia amyntor).

Other insects that can be found feasting on various parts of the tree are the basswood leafminer (Baliosus nervosus), basswood lace bug (Corythuca pallida), and linden twig gall gnat (Cecidomyia citrina).

Basswood nutlets are consumed by large game birds, as well as squirrels, chipmunks, and other small mammals. (These nutlets have a low viability, <70%, making it one of the most difficult North American trees to propagate.) Larger trees sometimes develop cavities which prove useful as nesting sites for birds and dens for squirrels and raccoons.