Platanus × hispanica is the botanical name of London plane tree. It is usually thought to be a hybrid of the Oriental plane, P. orientalis, with the American plane (American sycamore).
The London plane is a large deciduous tree growing to 20–35 m (exceptionally over 40 m) tall, with a trunk up to 3 m or more in circumference. The bark is usually pale grey-green, smooth and exfoliating, or buff-brown and not exfoliating. The leaves are thick and stiff-textured, broad, palmately lobed, superficially maple-like, the leaf blade 10–20 cm long and 12–25 cm broad, with a petiole 3–10 cm long.
Platanus × hispanica
The flowers are borne in one to three (most often two) dense spherical inflorescences on a pendulous stem, with male and female flowers on separate stems. The fruit matures in about 6 months, to 2–3 cm diameter, and comprises a dense spherical cluster of achenes with numerous stiff hairs which aid wind dispersal; the cluster breaks up slowly over the winter to release the numerous 2–3 mm seeds.
Platanus occidentalis is the botanical name of sycamore tree which is a close cousin of the London plane tree. The sycamore tree is easily recognized by its mottled exfoliating bark. The bark of the trunk and larger limbs flakes off in great irregular masses, leaving the surface mottled, and greenish-white, gray and brown. Sometimes the smaller limbs look as if whitewashed.
A sycamore can grow to massive proportions, typically reaching up to 30 to 40 meters (98 to 130 ft) high and 1.5 to 2 meters (4.9 to 6.6 ft) in diameter when grown in deep soils. The largest of the species have been measured to 51 meters (167 ft), and nearly 4 meters (13 ft) in diameter.
The sycamore tree is often divided near the ground into several secondary trunks, very free from branches. Spreading limbs at the top make an irregular, open head. Roots are fibrous. The trunks of large trees are often hollow.