Potentilla norvegica L.
Rough Cinquefoil, Norwegian Cinquefoil
Family - Rosaceae
Stems - To .75m tall, multiple from base, erect to ascending, herbaceous, from a taproot, branching, hirsute (hairs with swollen bases), green but becoming dark red in strong sun.
Leaves - Alternate, trifoliolate, petiolate, stipulate, much reduced upward. Stipules typically 4-5-lobed, to 3cm long, sparse pubescent above, ciliate-margined. Lobes acute. Petioles to 10cm long, hirsute, with adaxial groove. Lateral leaflets sessile, hirsute, ovate-oblong, to 5cm long, 3cm broad, serrate. Teeth acute, often with reddish tips. Terminal leaflet oval to broadly elliptic, on petiolule to 7mm long, hirsute.
Inflorescence - Axillary bracteate cymes. Pedicels to 9mm long(in flower), elongating in fruit, pilose to hirsute.
Flowers - To +/-1.2cm broad. Petals 5, distinct, yellow, glabrous, emarginate, 3.5mm long, 3mm broad. Stamens many(+/-20). Filaments yellowish, to 2mm long, glabrous. Anthers yellow, .4mm broad. Carpels many, yellowish. Hypanthium flattish, 5-6mm in diameter, densely pubescent. Sepals 5, accrescent, subtended by 5 bracts. Sepals and bracts deep green and typically with reddish tips. Sepals acuminate, 5mm long, 3mm broad at base. Bracts lance-oblong, 4-5mm long, 2mm broad, acute, ciliate-margined, appressed pubescent. Achenes brownish, rugose, to 1.3mm long.
Flowering - May - October.
Habitat - Fields, meadows, pastures, prairies, roadsides, railroads.
Origin - Native to U.S.
Other info. - This plant is found scattered throughout the state of Missouri. Our plants belong to variety norvegica which has hirsute stems and leaves. Another variety, var. labradorica (Lehm.) Fern., has glabrous stems and leaves but does not occur in our area.
Photographs taken at the Kansas City Zoo, 7-3-00, in Pictured Rocks National Seashore, MI., 7-21-02, and in the Ozark Scenic Riverways, Shannon County, MO., 5-18-03.