Potentilla norvegica.Fontenelle Nature Association.www.fnanaturesearch.org (Accessed 4/2014).

Potentilla norvegica is an annual or short-lived perennial herb, from a simple root, to 60 cm tall stout, hairy, leafy, branched, often red in full sun, stipules wing-shaped at base of leaf stalk. 

Leaves alternate, 3-parted, leaflets widest above middle, to 8 cm, hairy, green on both sides, margin coarsely toothed, lower leaves stalked, upper leaves stalkless. 

Flowers yellow, to 1 cm wide, 5 petals, calyx lobes slightly longer than petals, in tight clusters; self-fertile (agamospermy), (Mulligan and Kevan 1973); inflorescence branched, leafy; blooming and fruiting June-Oct. (Hough 1983). 

Fruit dry, a head of achenes, covered by enlarged calyx; seeds numerous 0.1 cm, pale brown, shallowly ridged. 

Wetland status: FACU. 

Frequency in NYC: Infrequent. 

Origin: Native and European. 

Habitat: Open areas, roadsides, fields. 

Note: Attacked by the fungi; Fabraea dehnii, Marssonina potentillae, Peronospora potentillae, Phoma potentillica, among others (Werner and Soule 1976).