Stems 12–60 cm, erect with hirsute foliage. Basal leaf blades cordate, 2–6 cm long, ternate, the sessile leaflets twice lobed. Flowers with petals 7–13 mm long, ca. twice as long as the hirsute sepals. Achenes compressed, 2–3 mm long, glabrous with a hooked beak ca. 1 mm long; heads hemispheric, 5–8 mm high (
Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Ranunculus and
Potentilla can be look-alikes because some species exhibit symmetrical flowers composed of 5 green sepals and 5 bright yellow petals that surround many ovate achenes (fruits).
Ranunculus species are in Family Ranunculaceae. Flowers exhibit shiny yellow petals, sepals that are separated to their base, and lack bracts between the sepals. In generalizing and looking from a distance, plants don’t appear hairy and seem rather darker green and glossier. Achenes are beaked.
Potentilla species are in the Family Rosaceae. Yellow-flowered forbs tend to have matted yellow petals, sepals united at their base and at least partially united to the ovary (forming a hypanthium), and often have bracts between the sepals. In generalizing and looking from a distance, plants often appear hairy and lighter or dull green. Achenes are not beaked.
Sharpleaf Buttercup -
Ranunculus acriformis, native and desirable:
* Basal leaf blades are broadly ovate to cordate in outline, deeply 3-divided (ternate). Sepals reflexed. Ultimate leaf segments are less numerous.
* Beak of the achene is about 1mm long and more compressed.
* Collectively the fruits are hemispheric in side-view.
Tall Buttercup -
Ranunculus acris, exotic and Noxious:
* Basal leaf blades pentagonal (5-sided) in shape that are mostly deeply divided into about 3 palmate lobes that again deeply divided into 2-3 acute segments. Ultimate leaf segments are more numerous.
* Beak of the achene is about 0.5 mm long.
* Sepals spread outwards.
* Collectively the fruits are globose in side-view.
POLLINATORS The following animal species have been reported as pollinators of this plant species or its genus where their geographic ranges overlap:
Bombus auricomus,
Bombus bifarius,
Bombus nevadensis, and
Bombus bimaculatus (Macior 1968, Thorp et al. 1983).
