of the 35th parallel. Time of flowering varies by several weeks depending on the latitude; early May in Canada and early June in the extreme southern extent. Leaf drop in fall occurs between early and late October depending on the latitude. The flowers are fragrant and insect-pollinated. The fruit is a small, globose, downy, hard and dry cream-colored nutlet with a diameter of .USDA NRCS Tree Guide: Tilia americana (pdf file) Ecology American basswood is dominant in the sugar maple–basswood forest association, which is most common in western Wisconsin and central Minnesota, but occurs as far east as New England and southern Quebec in places that have mesic soil with relatively high pH. It also has minor occurrence in many other forest cover types. Its flowers provide abundant nectar for insects. The seeds are eaten by chipmunks, mice, and squirrels. Rabbits and voles eat the bark, sometimes girdling young trees. The leaves serve as food for caterpillars of various Lepidoptera (see Lepidoptera which feed on Tilia). The ribbed cocoon maker species Bucculatrix improvisa has not been found on other plants. This species is particularly susceptible to adult Japanese beetles (an invasive species in North America) that feed on its leaves. The mushroom Pholiota squarrosoides is known to decay the logs of the tree. Cultivation and uses The American basswood can be propagated by cuttings and grafting as well as by seed. Propagated plants grow rapidly in a rich soil, but are susceptible to many pests. The American basswood is known for being one of the most difficult native North American trees to propagate from seed, as they not only have a low viability rate (approximately 30% of all seeds are viable), but quickly develop an extremely hard seed coating that may delay germination for up to two years. If planting them, it is recommended to gather the seeds in early autumn and sow them before they dry out and form a coating. This will then allow germination to occur immediately. Overall, seeds are not a major part of the tree's reproductive strategy and it instead mostly spreads by self-coppicing. All juvenile basswoods coppice extremely readily, and even old trees will often sprout from the stump if cut. The American basswood is recommended as an ornamental tree when the mass of foliage or a deep shade is desired; no native tree surpasses it in this respect. It is often planted on