About 1 to 1 1/2-inches around, they are green at first, turning brown as the seeds within mature. These clusters develop over the season into seed balls that are brown and fuzzy. A yellowish green, both male and female are inconspicuous. They are formed in round clusters about 1 inch in diameter. The flowers emerge in late May or early June about the same time that the leaves show.
They emerge in late spring, most dropping in December. They have smooth, dull medium green surfaces and paler undersides with hairy veins. The leaves are coarse and resemble maple leaves in shape and have 3 to 5 sharply pointed lobes and may measure up to 6 or 8 inches long and 8 or 10 inches across. London plane trees are the best trees in New York City for carbon storage and sequestration. It also comprises 4% of New York City trees, but 14% of the city’s total leaf area and it gives a lot prettier, shady, air-filtering, evaporative-cooling leaves per single trunk than most of the other species in a city. A member of the sycamore family, the first record of the tree was in 1663 when the hybrid of the American and oriental Plane tree was found growing in London, where it is the dominant street tree. It might also be called the tree with the camouflage or jigsaw puzzle bark. The most striking feature of the London Plane Tree is its flaking bark that peels to reveal a lighter colored bark underneath. London Plane Tree – Platanus x acerifolia