Ginkgo biloba L. (China) – Commonly planted as an ornamental tree in Belgium but only exceptionally found as an escape from cultivation or garden throw-out. Two saplings (ca. 30 cm tall) were recorded in open woodland in Neerpelt in 2011 (see also: http://waarnemingen.be/waarneming/view/61614269), possibly from discarded garden waste.
Despite being cultivated since ca. 1770 in western Europe (De Koning & al. 2000) Ginkgo biloba is only exceptionally reported as an escape (no records, for instance, from the British Isles; Clement & Foster 1994). The same holds true for North America where saplings are very rarely found in the vicinity of planted trees. Seeds of ginkgo are almost certainly dispersed by birds, possibly crows (Whetstone 1993).
Literature:
Andrews S. (1996) Tree of the year: Ginkgo biloba. Int. Dendrol. Soc. Year Book 1995: 14-31.
Clement E.J. & Foster M.C. (1994) Alien plants of the British Isles. BSBI, London: XVIII + 590 p.
De Koning J., Van den Broek J.W., Van de Laar H.J. & Fortgens G. (2000) Nederlandse dendrologie (13e druk). H. Veenman & zonen, Ede: 585 p.
Franklin A.H. (1959) Ginkgo biloba L.: historical summary and bibliography. Virginia J. Sc. N.S. 10: 131-176.
Hemke E. (1977) Der Ginkgo im Bezirk Neubrandenburg. Botanischer Rundbrief für den Bezirk Neubrandenburg 7: 98-102.
Herrera C.M. (2001) Assessing the potential for the stomatal characters of extant and fossil Ginkgo leaves to signal atmosphere CO2 change. Amer. J. Bot. 88: 1309-1315.
Hori T., Ridge R.W., Tulecke W., Del Tredici P., Tremouillaux Guiller J. & Tobe H. (eds.) (1997) Ginkgo biloba: a global treasure. From biology to medicine. Tokyo, Springer-Verlag.
Oliver J. (2002) Young dioecious trees, sex unknown. BSBI News 90: 28-29.
Schmid M. & Schmoll H. (eds.) (1994) Ginkgo. Ur-Baum und Arzneipflanze: Mythos, Dichtung und Kunst. Stuttgart, Wissenschaftliche Verlagsgesellschaft mbH: 135p.
Whetstone R.D. (1993) Ginkgoaceae. In: Flora of North America Editorial Committee (eds.), Flora of North America, vol. 2. Oxford University Press, New York-Oxford: 350-351.