American basswood is native to the north-eastern United States and southern Canada, though in cultivation it can grow even further north. In the wild it prefers dry or somewhat moist, normal to rich soil in broadleaf or mixed forest, but also occurs on rocky ground.
American basswood is an attractively shaped tree with a single trunk and broad rounded crown. The slightly drooping branches are pale grey, clearly visible in winter. The dark leaves are large compared with large leaved lime (T. platyphyllos), with upper and lower surfaces (approximately) the same shade of green. Flowers are bell-shaped, hanging in fan-shaped clusters of 4-10. The fruit is quite large, diameter about 8mm (0.3 in.) round and smooth. Autumn leaf colour is a beautiful yellow.
Often used in parks throughout North America and Europe, American basswood is hardy in southern Finland. At Mustila it can be seen near Juhlapaikka or Festival area, growing in warm deep soil on Etelärinne (Southern Slope) where many other eastern American species have been planted. Some of the basswood specimens here have been grown from seed collected by Mustila’s own expeditions.