Potentilla recta L. (Euras., N-Afr.) – A rather rare but increasing, naturalized alien (mostly an escape from cultivation). Probably first documented in 1824 (Durand 1899). Already well-naturalized locally in the 19th century, for instance in artificial meadows in Korbeek-Lo (in the 1860’s already said to be present in abundance for more than 30 years). Since that time also recorded in numerous localities in the surroundings of Brussels (Watermaal-Bosvoorde, Vorst, Laken, etc.), mostly associated with railway tracks. Other long time occurrences are known, for instance, from Averbode (since at least 1939), Balen-Wezel (since 1920), Brecht (Groot Schietveld, since 1956), etc. At present, Potentilla recta is more or less widely naturalized but by far most frequent in the Kempen in Flanders (Verloove 2006). In Wallonia it is more evenly distributed.
Potentilla recta is usually considered an escape from cultivation but some of the records seem to be associated with other vectors of introduction (for instance in port areas, etc.). In the past, it was also recorded in clover fields.
The taxonomy of Potentilla recta is very complex, controversial and badly in need of further study. In Belgium two fairly distinct entities can be recognized and these are given subspecies rank, following Kurtto & al. (2004) (see also Euro+Med Plantbase). They are opposed in the following couplet:
1 Petals sulphureus or cream === subsp. recta
Petals pure yellow === subsp. obscura
Subsp. recta (syn.: var. sulphurea Lapeyr.) is by far the commoner of the two and more or less widely naturalized, especially in the Kempen in Flanders (Verloove 2006). In Wallonia it is more widely scattered, without displaying dense concentrations. See here for an up-to-date distribution map for Belgium: http://waarnemingen.be/soort/view/7254. Subsp. obscura (Willd.) Arcang. (syn.: P. obscura Willd., P. recta var. obscura (Willd.) W.D.J. Koch), a southeastern vicariant (see Kurtto & al. 2004), is much less frequent. A “var. obscura Fonsny et Coll.” was already cited by Durand (1899) but it is uncertain whether or not this corresponds with the taxon currently found (in the herbarium petal colour readily fades after dessication). Lawalrée reliably recorded subsp. obscura in 1950 at the Brussels railway junction Nord-Midi but did not refer to it in his monographic work on Belgian Rosaceae (Lawalrée 1959). More recently, it has been recorded since 2009, at first in Sint-Katherina-Lombeek (Ternat). Since then also found near a cemetery in Adinkerke in 2011 (not confirmed subsequently) and in the Antwerp and Ghent port area in 2012. In 2013 also seen at two localities around Kortemark (both by railway sidings). At least in one of these subsp. obscura occurs in quantity and looks perfectly established. It is also naturalized in quantity on the slopes of a coal mining spoil heap in Genk (Winterslag). It differs from subsp. recta in having darker yellow petals and wider, obovate leaflets. Moreover, its stems are usually purplish-red.
 |
 |
 |
 |
 |
 |
 |
 |
Selected literature:
Bayon N.D. (1995) Nueva cita para la flora Patagónica (Argentina): Potentilla recta (Rosaceae). Bol. Soc. Argent. Bot. 30(3-4): 149-151.
Diard L. (2000) Quelques indications sur la répartition de Potentilla recta L. en Ille-et-Vilaine. E.R.I.C.A. 13: 8-12.
Durand T. (1899) Phanérogames. In: De Wildeman E. & Durand T., Prodrome de la flore belge. A. Castaigne Editeur, Bruxelles: 1112 p.
Ertter B., Elven R., Reveal J.L. & Murray D.F. (2014) Potentilla. In: Flora of North America Editorial Committee (eds.), Flora of North America, vol. 9. Oxford University Press, New York-Oxford: 121-218. [available online at: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=126635]
Evert E.F. (1982) Noteworthy collections: Wyoming. Madrono 29(2): 124-125.
Kurtto A., Lampinen R. & Junikka L. (eds.) (2004) Atlas Florae Europaeae. 13. Rosaceae (Spiraea to Fragaria, excl. Rubus). The Committee for Mapping the Flora of Europe & Societas Biologica Fennica Vanamo, Helsinki: 320 p.
Lawalrée A (1959) Potentilla. In: Robyns W. (ed.), Flore Générale de Belgique, vol. 3, fasc. 2. Jardin Botanique de l’Etat, Bruxelles: 281-306.
Puntieri J.G. & Brion C. (2006) Sobre la presencia de Potentilla recta (Rosaceae). Hickenia 3(66): 297. [available online at: http://www2.darwin.edu.ar/Vol3/h3_66.pdf]
Puntieri J.G. & Brion C.A.M. (2005) Nuevas citas para la flora argentina:
Collomia grandiflora (Polemoniaceae) y Potentilla recta (Rosaceae). Hickenia 3(54): 227-232. [available online at: http://www2.darwin.edu.ar/Vol3/h3_54.pdf]
Rico E., Martínez-Ortega M.M., Delgado L., Báez A. & Martínez R. (2003) A multivariate morphometric study of the Iberian representatives of Potentilla sect. Recta (Rosaceae). Folia Geobot. 38(1): 35-48.
Soják J. (1993) Taxonomische Bemerkungen zu einigen mediterranen Potentilla-Sippen. Preslia 65: 117-130.
Verloove F. (2002) Ingeburgerde plantensoorten in Vlaanderen. Mededeling van het Instituut voor Natuurbehoud n° 20: 227 p.
Verloove F. (2006) Potentilla recta. In: Van Landuyt W., Hoste I., Vanhecke L., Van den Bremt P., Vercruysse W. & De Beer D., Atlas van de flora van Vlaanderen en het Brussels gewest. Instituut voor Natuur- en Bosonderzoek, Nationale Plantentuin van België en Flo.Wer: 708.
Werner P.A. & Soule J.D. (1976) The biology of Canadian weeds: 18. Potentilla recta L., P. norvegica L., and P. argentea L. Canad. J. Plant Sci. 56(3): 591-603. [available online at: http://pubs.aic.ca/doi/pdf/10.4141/cjps76-095]