Flowering and Fruiting- The fragrant, yellow-white, flowers are borne on loose cymes on long stalks attached to leafy bracts. Flowering generally occurs in June but can begin in late May or early July, depending on latitude and annual variations in temperature. Flowering follows initial leaf-out and lasts approximately 2 weeks. During this period, all stages of floral development are present on a single tree or even in a single inflorescence (4 to 40 flowers per inflorescence). The flowers attract a number of insect pollinators. In a study of the pollination biology, 66 species of insects from 29 families were identified as pollinators of the  flowers.

Bees and flies were the most common diurnal pollinators; moths were the primary nocturnal visitors. The fruit, a nutlike drupe 5 to 10 mm (0.2 to 0.4 in) in diameter, usually contains one seed but in collections from both open- and forest-grown trees, 12 percent of the fruit contained two seeds and less than 1 percent contained three seeds. The seeds have a  crustaceous seed coat (testa), a fleshy yellowish endosperm, and a well-developed embryo. A variety of forms of fruit and seed have been noted, including egg-shaped, round, onion-shaped, conical, and pentagonal. Individual trees tend to consistently produce fruit of a particular form and size.

Seed Production and Dissemination- Fruits ripen in September and October and are soon dispersed by such mechanisms as wind, gravity, and animals. although the flower bracts are reported to aid in wind dispersal, fruits rarely are carried more than one or two tree lengths from the parent. In addition to their limited role in seed dispersal, bracts may act as "flags" to attract pollinators (especially nocturnal ones) to the inflorescences. Animals probably increase the seed dispersal significantly.

Damaging Agents- Basswood plantations established on weed infested old-field sites are susceptible to girdling by mice and voles, and completely girdled trees die. In a southern Ontario plantation, 44 percent of the basswood stems were completely girdled and 39 percent were partially girdled. The species responsible for the girdling, the meadow vole, does most of this damage feeding beneath the snow. Rabbits also feed heavily on seedlings and small saplings in both plantations and natural stands.

Basswood seeds are eaten by mice, squirrels, and chipmunks, thus reducing the chances of seedling establishment. Many different insects attack basswood, but few serious insect problems exist. The linden borer (Saperda vestita) makes long, irregular tunnels, particularly at the base of the tree, and may damage weak, very young, or overmature trees. Local infestations of defoliators may occur. The primary ones include the linden looper (Erannis tiliaria), basswood leafminer (Baliosus nervosus), spring cankerworm (Paleacrita vernata), fall cankerworm (Alsophila pometaria), whitemarked tussock moth (Orgyia leucostigma), gypsy moth (Lymantria dispar), and forest tent caterpillar (Malacosoma disstria). In New England, American basswood is a highly preferred host for gypsy moth, while in southern Quebec, it was classified as intermediate in susceptibility to gypsy moth defoliation.

The foliage is host to various diseases-anthracnose (Gnomonia tiliae), black mold (Fumago vagans), and leaf spot (Cercospora microsora)-but none seem to do serious damage. The wood of basswood decays easily and once exposed can be host to many of the common hardwood decay organisms such as the yellow cap
fungi (Pholiota limonella) and Collybia velutipes. Phellinus igniarius, Ustulina deusta, and nectria canker (Nectria galligena) also are found on basswood. Little defect is encountered in basswood when harvested before it reaches 120 years of age. Beyond this age, the chances of losses due to decay are greatly increased. Cull studies in the forests of Ontario indicate that yellow-brown stringy rot was the most common bole defect encountered; brown stain, some incipient yellow rot, and green stain were also found. The thin bark of this species is easily damaged by fire. Basswood is one of the hardwoods least susceptible to late spring frosts.

Special Uses - Basswood has relatively soft wood that works exceptionally well and is valued for hand carving and has many other uses including cooperage, boxes, veneer, excelsior, and pulp. Basswood is economically important for timber, especially in the Great Lakes States. The inner bark, or bast, can be used as a source of fiber for making rope or for weaving such items as baskets and mats. 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. Throughout the Eastern United States, basswood is frequently planted along city streets.