See text Platanus (/ˈplætənəs/ PLAT-ən-əss[1]) is a genus consisting of a small number of tree species native to the Northern Hemisphere.

[4] The flowers are reduced and are borne in balls (globose heads); 3–7 hairy sepals may be fused at the base, and the petals are 3–7 and are spatulate.

The base of the leaf stalk (petiole) is enlarged and completely wraps around the young stem bud in its axil.

[citation needed] The mature bark peels off or exfoliates easily in irregularly shaped patches, producing a mottled, scaly appearance.

[6] Both lineages have been affected by reticulate evolutionary processes in the past (ancient or recent hybridization and introgression):[6][7][9] The genus Platanus exemplarily illustrates the concept of a Coral of Life, a species network.

[11] Despite the geographic separation between North America and Old World, species from these continents will cross readily resulting in fertile hybrids such as the London plane, which is an anthropogenic hybrid (cultivar) between the North American P. occidentalis sensu stricto (ANA clade) and the Mediterranean P. orientalis (PNA-E clade).

interior Nixon & Poole, restricted to Guanajuato, Hidalgo, Querétaro and San Luis Potosí, and of hybrid origin[10] s.str: 1–3[10] ANA clade syn Platanus occidentalis var.

After one such mass attack which affected schoolchildren in classrooms with open windows densely surrounded by plane tees, children had to be admitted to hospital, where they were treated and recovered without ill effects.

It was found that the symptoms were due to the fine star-shaped trichomes (hairs) on all parts of platanus trees, which are broken off by strong wind after a prolonged dry period.

The school incident took place after a dry period, with a fairly high temperature of 29 °C (84 °F), and wind blowing at 50 km/h (31 mph).

It is not recommended that trees in cities be felled, as they are beneficial; in particular the platanus trichomes act as biofilters for air pollutants.

Where there are urban concentrations presenting a risk, seasonal spraying of trees with a solution of apple pectin can prevent the star hair from breaking off.

[16] Handel's opera Serse has a famous aria, "Ombra mai fu", which the title character sings in praise of his favorite plane tree.

The plane tree has been a frequent motif featured in Classical Chinese poetry as an embodiment of sorrowful sentiments due to its autumnal shedding of leaves.

[citation needed] The legendary Dry Tree first recorded by Marco Polo was possibly a platanus.