Mazus Lour.
As currently understood, Mazus is a genus with ca. 20-35 species in eastern Asia, New Zealand and Australia (Mabberley 2008). It is most diverse in China where most of the species occur (Hong & al. 1998). Several species are economically important: five stoloniferous perennials are cultivated as carpeting ornamentals in Europe (Mill 2000; Jäger & al. 2008). Out of these, at least M. miquelii Makino and M. reptans N.E. Brown have been recorded as a escapes in Europe. Pringle (2018) pointed out that plants sometimes called M. reptans should be included in M. miquelii. An additional species, the annual Mazus pumilus (Burm.f.) Steenis, is a common weed throughout the (sub-) tropics and has been recorded in Belgium as well.
1 Annual, stolons absent. Corolla 7-9 mm === Mazus pumilus
1 Stoloniferous perennial. Corolla 13-22 mm === M. reptans
Literature:
Barker M.R. (1991) A taxonomic revision of Mazus Lour. (Scrophulariaceae) in Australasia. In: Banks M.R. & al. (eds.), Aspects of Tasmanian Botany: a tribute to Winifred Curtis. Hobart, Tasmania, Royal Society of Tasmania: 85-94. [available online at: http://eprints.utas.edu.au/14668/1/Barker_A_toxonomic_revision.pdf]
Hong D., Yang H., Jin C., Fischer M.A., Holmgren N.H. & Mill R.R. (1998) Scrophulariaceae. In: Wu Z.Y. & P.H. Raven (eds.), Flora of China, vol. 18. Science Press, Beijing, and Missouri Botanical Garden Press, St. Louis: 1-212. [available online at: http://flora.huh.harvard.edu/china/PDF/PDF18/mazus.pdf]
Hsieh T.H. (2000) Revision of Mazus Lour. (Scrophulariaceae) in Taiwan. Taiwania 45(2): 131-146. [available online at: http://tai2.ntu.edu.tw/Taiwania/pdf/tai.2000.45.2.131.pdf]
Jäger E.J., Ebel F., Hanelt P. & Müller G. (eds.) (2008) Rothmaler Band 5. Exkursionsflora von Deutschland. Krautige Zier- und Nutzpflanzen. Springer Verlag, Berlin: 880 p.
Li H.L. (1954) The genus Mazus. Brittonia 8: 29-38.
Mabberley D.J. (2008) Mabberley’s plant-book (3th ed.). Cambridge University Press, Cambridge: XVIII + 1021 p.
Mill R.R. (2000) Mazus. In: Cullen J. & al. (eds.), The European Garden Flora, vol. 6. Cambridge University Press, Cambridge: 280-282.
Pringle J.S. (2018) The Identification, Nomenclature, and Naturalized Distribution of Mazus miquelii (Mazaceae) in North America. Castanea 83(2): 216-223.
Rabeler R.K. & Freeman C.C. (2013) Mazaceae. Flora of North America, Provisional Publication. Flora of North America Association. February 15, 2013. [available online at: http://floranorthamerica.org/files/Mazaceae03f%20SI%20CH%20for%20web.pdf]