Sphaeralcea A. St.-Hil.
Sphaeralcea is an entirely American genus with about 50 species that are mostly found in arid regions (La Duke 2015). More than half of them occur in North America, the others in Mexico, Argentina, Bolivia, Brazil, Chile and Paraguay. A few species are cultivated as ornamentals, also in Europe (Le Huquet 1997, Jäger & al. 2008), but probably none is really widespread in cultivation. At least one, S. bonariensis, is widespread and weedy in South America. It is established outside of its native range and is occasionally recorded as an adventive as well, also in Belgium.
Atwood N.D. & Welsh S.L. (2002) Overview of Sphaeralcea (Malvaceae) in southern Utah and northern Arizona, U.S.A., and description of a new species. Novon 12(2): 159-166. [available online at: http://www.biodiversitylibrary.org/page/642737#page/159/mode/1up]
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.
Kearney T.H. (1935) The North American species of Sphaeralcea subgenus Eusphaeralcea. Univ. Calif. Publ. Bot. 19: 1-128.
Krapovickas A. (1949) Las especies de Sphaeralcea de Argentina y Uruguay. Lilloa 17: 179-222.
La Duke J. (2015) Sphaeralcea. In: Flora of North America Editorial Committee (eds.), Flora of North America North of Mexico, vol. 6. Oxford University Press, New York: 357-369. [available online at: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=130861]
Le Huquet J.A. (1997) Sphaeralcea. In: Cullen J. & al. (eds.), The European Garden Flora, vol. 5. Cambridge University Press, Cambridge: 222-223.