Thladiantha dubia Bunge (Korea, China) – An exceptional and probably ephemeral alien. Recorded only twice so far, at first in 2010 at the decantation basins of the sugar refinery of Tienen. In 2020 it was also observed on the bank of river Durme in Heindonk (Willebroek).
At this first locality Thladiantha dubia was initially identified as Cucumis melo, a species which it resembles superficially. However, it has more deeply cordate, unlobed leaves with semicircular sinuses, larger corollas and very distinct, reflexed calyx segments.
Thladiantha dubia is cultivated as an ornamental and for its edible fruit. In parts of south central Europe it has become naturalized in recent years, for instance in Austria and Croatia.
Selected literature:
Alegro A., Bogdanović S., Rešetnik I. & Boršić I. (2010) Thladiantha dubia Bunge (Cucurbitaceae), new alien species in Croatian flora. Natura Croatica 19(1): 281-286. [available online at: http://hrcak.srce.hr/index.php?show=clanak&id_clanak_jezik=82723]
Chrtková A. (1983) Poznamy k nekterym adventivnim druhum z celedi Cucurbitaceae v Ceskoslovensku. Zpravy Cesk. Bot. Spol. CSAV 18(1): 15-25.
Jentsch H. (1984) Zum Vorkommen von Thladiantha dubia Bunge im Spreewald. Gleditschia 12(1): 83-84.
Kuluev B.R., Shvetsb D.Y., Golovanovc Y.M. & Probatova N.S. (2019) Thladiantha dubia (Cucurbitaceae) in the Republic of Bashkortostan as a Dangerous Weed with High Invasive Potential. Russian Journal of Biological Invasions 10(2): 160-170. [available online at: https://www.researchgate.net/publication/333881457_Thladiantha_dubia_Cuc...
Leute G.H. & Sembach W. (1984) Die Verbreitung der Quetschgurke (Thladiantha dubia Bunge, Cucurbitaceae) in Kärnten und deren Auftreten als Maisunkraut. Carinthia II, 94: 37-45. [available online at: http://www.landesmuseum.at/pdf_frei_remote/CAR_174_94_0037-0045.pdf]
Zounek F. (1936) Thladiantha dubia na Moravě. Příroda 29: 29.