Platanus L. is a genus with ca. 10 species that are dispersed throughout Central and North America, SW Asia, SE Europe and also counts one species in SE Asia (Laos and N Vietnam). A few species and a hybrid are more or less widely cultivated as ornamental trees. Two of these have been recorded as escapes from cultivation in Belgium.
1 Fruiting branchlets with 3–6 infructescences. Leaves deeply (3-)5- or 7-lobed with central leaf lobe longer than wide === Platanus orientalis
Fruiting branchlets with 1 or 2 infructescences. Leaves (3-)5(-7)-lobed with central leaf lobe not longer than wide (except in some cultivars) === P. hispanica
Literature
Denk T. & Tekleva M.V. (2006) Comparative pollen morphology and ultrastructure of Platanus: implications for phylogeny and evaluation of the fossil record. Grana 45(3): 195-221. [available online at: https://www.tandfonline.com/doi/full/10.1080/00173130600873901]
Depape G. & Brice D. (1966) Platanes actuels et Platanes fossiles. Rev. Gén. Bot. 73: 41-84.
Feng Y., Oh S.H. & Manos P.S. (2005) Phylogeny and historical biogeography of the genus Platanus as inferred from nuclear and chloroplast DNA. Syst. Bot. 30: 786-799. [available online at: https://www.researchgate.net/profile/Sang_Hun_Oh2/publication/250054393_...
Hsiao J.-Y. (1973) A numerical taxonomic study of the genus Platanus based on morphological and phenolic characters. Amer. J. Bot. 60: 678-684.
Kaul R.B. (1997) Platanaceae. In: Flora of North America Editorial Committee (ed.), Flora of North America, vol. 3. Oxford University Press, New York-Oxford: 358-361. [available online at: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=10703]
Leroy J.-F. (1982) Origine et évolution du genre Plantus (Platanaceae). Compt. R. Séances Acad. Sci., Ser. 3, Sci. Vie 295(3): 251-254.
Nixon K.C. & Poole J.M. (2003) Revision of the Mexican and Guatemalan species of Platanus (Platanaceae). Lundellia 6: 103-137. [available online at: https://repositories.lib.utexas.edu/handle/2152/32766]
Santamour F.S. (1972) Interspecific hybridization in Platanus. Forest Sci. 18(3): 236-239.
Suss H. & Muller-Stoll W.R. (1975) Zur Frage der Unterscheidung von Platanus-Arten nach dem Bau des Holzes. Feddes Repert. 86(1-5): 57-70.
Zhang Z.-Y.& Turland N.J. (2003) Platanaceae. In: Flora of China, vol. 9. Science Press, Beijing & Missouri Botanical Garden Press, St. Louis: 44–45. [available online at: http://flora.huh.harvard.edu/china/mss/volume09/Platanaceae.PDF]