Phrymaceae
Phrymaceae accommodates 13 genera from warm-temperate and tropical regions (Mabberley 2008). Its boundaries were considerably re-defined as a result of molecular phylogenetic studies (Beardsley & Olmstead 2002) and this new circumscription is now widely accepted (APG III 2009). Some genera traditionally placed in Scrophulariaceae now belong here. In Belgium one non-native genus is involved, Erythranthe (formerly Mimulus section Erythranthe).
A related genus, Mazus Lour., was also transferred to Phrymaceae (Mabberley 2008) but more recent studies by Reveal (2011) tend to place it in a family of its own, Mazaceae. One species, Mazus pumilus (Burm.f.) Steenis, is a common weed and is sometimes seen as a bonsai-weed in Belgian plant nurseries. Future occurrences in the wild are not unlikely (see also Desfayes 1997).
Literature:
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.
Beardsley P.M. & Olmstead R.G. (2002) Redefining Phrymaceae: the placement of Mimulus, tribe Mimuleae, and Phryma. Am. J. Bot. 89(7): 1093-1102.
Desfayes M. (1997) Mazus pumilus (Scrophulariaceae), adventice nouvelle pour l’Italie, et Lemna minuta (Lemnaceae) espèce nouvelle pour la province de Pavie. Saussurea 28: 65-66.
Mabberley D.J. (2008) Mabberley’s plant-book (3th ed.). Cambridge University Press, Cambridge: XVIII + 1021 p.
Reveal J.L. (2011) Summary of recent systems of angiosperm classification. Kew Bull. 66: 5-48.