Platanus racemosa aka California Sycamore

Platanus racemosa is known as California sycamore or western sycamore. It belongs to the plane tree family, Platanaceae. Its native range spans California and northern Baja California in Mexico. In California, it grows in the foothills and Coast Range. This broadleaf tree loses its leaves each year. It comes from a temperate region and grows fast.

In gardens, it reaches about 40–80 feet [12–24 metres] tall. Broader descriptions report heights up to 100 feet [30.5 metres]. Very large trees can have trunks 11 feet [3.4 metres] across. The crown forms an uneven, rounded shape with an open spread. Trees often grow with more than one trunk. The bark gives the tree much of its visual interest. Near the base, dark brown bark has furrows and scaly ridges. Higher on the trunk, the bark becomes smooth and pale. Young greenish-gray bark peels away to reveal nearly white bark beneath.

The leaves grow alternately along the twigs and have long stalks. Each simple leaf has three to five spreading, palmately arranged lobes. Leaf lengths range from about six to ten inches across sources. The edges may be smooth or have some teeth. The upper surface looks light green; the underside is paler. Fine pale hairs cover young leaves and gather along the midrib. Small, leaflike stipules sit where the leaf stalk meets the stem. Young twigs also bear fine hairs. As they age, they become smooth and reddish brown.

One tree carries separate male and female flowers. Both are tiny and grow in round clusters. Greenish-yellow male heads appear on new twigs. Larger, reddish female heads grow on older branches. The fruit forms hanging, ball-shaped clusters of tufted achenes. Three to seven fruit heads share a long stalk. The stalk breaks apart as the fruit matures. Wind carries the seeds away from the tree.

Grow this tree in sun or partial shade. It tolerates both heat and wind. Oregon State lists it as hardy to USDA Zone 7. Its pale upper bark and rounded crown give it landscape interest. Gardeners can prune it to form a clump of trunks. Its large mature size needs space in a garden.