The family limits of Passifloraceae dramatically changed as a result of recent molecular studies. It now includes Turneraceae and Malesherbiaceae (APG III 2009). All members originate in the tropical and warm temperate regions, especially in Africa and America. Only a single genus has been recorded in Belgium, Passiflora.
APG III (2009) An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants. APG III. Bot. J. Linn. Soc. 161(2): 105-121. [available online at: http://onlinelibrary.wiley.com/doi/10.1111/j.1095-8339.2009.00996.x/pdf]