Platanus occidentalis aka American Sycamore

American sycamore, Platanus occidentalis, is a large deciduous tree in the plane family. Other names include buttonwood, buttonball tree and American plane. It grows wild from southeastern Canada through the central and eastern United States. Its range runs from Maine and Ontario south to Florida and Texas. In the wild it favours lowland sites, and it grows biggest beside streams, rivers and on floodplains. Many regard it as the most massive native tree of eastern North America.

In gardens it usually reaches 75 to 100 feet (23 to 30 m) tall, with a spread of 50 to 70 feet (15 to 21 m). Rare trees top 150 feet (45 m). UK sources give a smaller figure of around 80 feet (25 m). Young trees look pyramidal. With age the crown becomes broad, rounded or irregular, carried on a few very thick limbs. Trunks often measure 3 to 8 feet (1 to 2.4 m) across. Growth is fast and the texture is coarse.

The bark is the main attraction. Brown and grey outer layers flake away in patches. This reveals a creamy white inner bark, so old trees look mottled from far off. Twigs are stout, orange-brown and zigzag, with no terminal bud. The leaf stalk base hides each bud until the leaf falls. Leaves are simple, alternate and 4 to 10 inches (10 to 25 cm) wide. Each has three to five pointed lobes and coarse teeth. They turn a dull yellow-brown in autumn.

Small, plain flowers open in spring, around March to April. Male flowers are yellowish and female flowers are red. They give way to fuzzy, round fruit balls up to about 1 inch (2.5 cm) across. Each hangs on a long stalk of 3 to 6 inches. The balls turn brown in autumn and stay on the tree into winter. They then break apart, and the wind carries the tiny seeds on downy tufts. Finches, juncos and chickadees eat the seeds.

The tree needs full sun and moist, deep soil. It copes with clay, sand, loam, acid or alkaline ground and wet sites. It also handles compacted soil, pollution and city conditions. It is hardy in USDA zones 4 to 9 and rated H6 in the UK. Gardeners use it as a shade tree, screen or large street tree. It also suits rain gardens. Deer seldom damage it. The hard wood has gone into furniture, butcher blocks, barrels and crates. Native Americans hollowed the trunks into canoes.

It does have drawbacks. Anthracnose can strip leaves and twigs in cool, wet springs. Canker, leaf spot, powdery mildew and bacterial leaf scorch also occur. Pests include sycamore lace bug, borers, scale, Japanese beetles, caterpillars and mites. Constant drops of twigs, leaves, bark and fruit make it messy in a lawn. Its strong roots can lift paving. The sweet spring sap can be boiled into syrup or sugar. Hairs on the fruit and leaves may irritate skin and airways, so wear gloves when handling the fruit.