Minuartia L.
Minuartia is a genus of ca. 175 species. Its center of diversity obviously lies in Eurasia (Europe, Turkey, former USSR) but some species extend further south to Mexico, Chile, Ethiopia, the Himalayas, etc. (Bittrich 1993, Rabeler & al. 2005). Two species are native in Belgium: Minuartia hybrida (Vill.) Schischkin and M. verna (L.) Hiern var. hercynica (Willk.) Friedrich (the latter confined to zinciferous soils) (Lambinon & Verloove 2012). Some species are cultivated as ornamentals (especially for the rock garden; e.g. Jäger & al. 2008) but, so far, none have been observed as an escape in Belgium.
Recent molecular studies have shown Minuartia to be polyphyletic. At least three subgenera need to be transferred to other genera (Harbaugh & al. 2010, Greenberg & Donoghue 2011). Dillenberger & Kadereit (2014) even suggested to split up the genus in 11 genera, native Minuartia verna being accommodated in Sabulina Reich. (as S. verna (L.) Reich.). Pending further study, Minuartia is here accepted in its traditional sense.
1 Perennial, mat-forming. Petals slightly longer than sepals (native) === Minuartia verna var. hercynica
Annual. Petals shorter than sepals === 2
2 Inflorescence compact. Longest pedicels ca. as long as sepals === M. mediterranea
Inflorescence lax. Longest pedicels 2-3x as long as sepals (native) === M. hybrida
Additional alien: Minuartia laricifolia (L.) Schinz et Thell. (Alps, Pyrenees, garden escape?).
Literature:
Bittrich V. (1993) Caryophyllaceae. In: Kubitzki K. et al. (eds.) The Families and Genera of Vascular Plants, vol. 2. Berlin, etc.: 206-236.
Dillenberger M.S. & Kadereit J.W. (2014) Maximum polyphyly: Multiple origins and delimitation with plesiomorphic characters require a new circumscription of Minuartia (Caryophyllaceae). Taxon 63(1): 64-88.
Greenberg A.K. & Donoghue M.J. (2011) Molecular systematics and character evolution in Caryophyllaceae. Taxon 60(6): 1637-1652. [available online at: http://donoghuelab.yale.edu/sites/alienplantsbelgium.bedefault/files/208_greenberg_taxon11_0.pdf]
Halliday G. (1964) Minuartia. In: Tutin T.G. & al. (eds.), Flora Europaea, vol. 1. Cambridge University Press, Cambridge: 125-132.
Harbaugh D.T., Nepokroeff M., Rabeler R.K., McNeill J., Zimmer E.A. & Wagner W.L. (2010) A new lineage-based tribal classification of the family Caryophyllaceae. Int. J. Pl. Sci. 171: 185-198. [available online at: http://si-pddr.si.edu/bitstream/10088/9723/1/bot_Harbaugh_et_al_2010-Caryophyllaceae.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.
Lambinon J. & Verloove F. (avec coll. Delvosalle L., Toussaint B., Geerinck D., Hoste I., Van Rossum F., Cornier B., Schumacker R., Vanderpoorten A. & Vannerom H.) (2012) Nouvelle Flore de la Belgique, du Grand-Duché de Luxembourg, du Nord de la France et des Régions voisines (Ptéridophytes et Spermatophytes). Sixième édition. Jardin botanique national de Belgique, Meise: CXXXIX + 1195 p.
McNeill J. (1962) Taxonomic studies in the Alsinoideae I: Genetic and infrageneric groups. Notes from the Royal Botanic Garden, Edinburgh 24: 79-155.
McNeill J. (1963) Taxonomic studies in the Alsinoideae II: A revision of the species in the Orient. Notes from the Royal Botanic Garden, Edinburgh 24: 241-404.
McNeill J. (1967) Minuartia. In: Davis P.H. (ed.), Flora of Turkey and the East Aegean Islands, vol. 2: 38–67. Edinburgh, Edinburgh University Press.
Rabeler R.K. (2005) Lepyrodiclis. In: Flora of North America Editorial Committee (eds.), Flora of North America, vol. 5. Oxford University Press, New York-Oxford: 116-136.
Schischkin B.K. (1936) Minuartia. In: Komarov V.L. (ed.), Flora of the USSR, vol. 6: 482-516. Jerusalem, Israel Program for Scientific Translation.