Potentilla Norvegica

https://fsus.ncbg.unc.edu/main.php?pg=show-key.php&highlighttaxonid=3150#K39971L3a
https://gobotany.nativeplanttrust.org/dkey/potentilla/#c16
http://www.namethatplant.net/plantdetail.shtml?plant=3255
https://www.inaturalist.org/observations/identify?quality_grade=research&verifiable=true&per_page=100&taxon_id=55732&place_id=1&preferred_place_id=1&photos=true&ident_user_id=alexey_pot

Key Characteristics:
Norwegian cinquefoil produces a basal rosette of trifoliate leaves from a taproot. Lower leaves continue to be trifoliate.
In maturity, it has a green or red stem growing erect up to about 50 cm (20 in) in maximum length and branching in its upper parts. The flowering stalks have long spreading hairs which are stiff, tubercle-based, to 3 mm long.
The leaves are stalked and are either divided into five leaflets, or have three leaflets with the terminal leaflet being divided into three lobes. Each leaflet is up to 5 cm (2 in) long and is widely lance-shaped with toothed edges. The basal leaves have narrow, sharp-tipped stipules while the upper leaves have elliptical stipules which are longer than the leaf stalks.
The inflorescence is a terminal cyme of several flowers. 5 green bracts. Each flower has five rounded yellow petals 3-5mm long inside a calyx of hairy, pointed sepals with reddish tips. Petals are slightly shorter than to subequal in length to the sepals. There are fifteen to twenty stamens, a separate gynoecium and many pistils. The calyx lengthens after flowering and the fruit is a cluster of pale brown achenes, green-brown to brown, striate-ribbed.

Be careful to distinguish it from:
Potentilla recta:
lower leaves with mostly 5 or 7 leaflets and petals usually 7-12 mm long, slightly to evidently Longer petals than the sepals
(vs. P. norvegia, with the lower leaves with 3 leaflets and petals 2-5 mm long, slightly Shorter petals than to as long as the sepals).
Potentilla rivalis:
androecium with mostly 10 stamens bearing anthers 0.2–0.3 mm long, stems villous, and petals 1.3–3 mm long, petals conspicuously Shorter than the sepals
(vs. P. norvegica, with the androecium with 15–20 stamens bearing anthers 0.3–0.5 mm long, stems hirsute, and petals 2–5 mm long, petals slightly Shorter than to subequal in length to the sepals).
Potentilla indica:
Spreads along creeping stolons, rooting and producing crowns at each node. Trifolate leaflets have equivalent petioles for all 3. Crennate/serrate leaf margin.
(vs. P. norvegica with a basal rosette. Center of rosette is producing more leaflets upwards. terminal leaflet has a longer petiole. Deeper leaf margin valleys.)

Posted on April 25, 2024 03:51 PM by sarah_oberlin