Straightbeak Buttercup

The first two varieties ( Ranunculus orthorhynchus var. orthorhynchus and R . orthorhynchus var. platyphyllus ) are rather weak, intergrading extensively in California and Oregon. By contrast, R . orthorhynchus var. bloomeri often grows with the others with little or no intergradation (although intermediate populations are found in some areas), and it has been treated as a distinct species, R . bloomeri , by many taxonomists.

Stems nearly erect or decumbent, never rooting nodally, hispid, strigose, or glabrous, base not bulbous. Roots sometimes fleshy and ± tuberous. Basal leaf blades narrowly ovate to oblong or semicircular in outline, simple to 3-5-lobed or -foliolate, 2.8-12.5 × 2.5-14 cm, leaflets or segments undivided or 1-2×-lobed or -parted, ultimate segments circular to linear, margins dentate, crenate, or entire, apex rounded to narrowly acute. Flowers: receptacle hispid; sepals reflexed 1-2 mm above base, 5-11 × 2-4 mm, hispid, hirsute, or glabrous; petals 5-6, abaxially yellow or red, adaxially yellow, 8-18 × 4-11 mm. Heads of achenes hemispheric to ovoid, 5-13 × 6-10 mm; achenes 2.8-4.5 × 1.8-3.2 mm, glabrous, margin forming narrow rib 0.1-0.2 mm wide; beak persistent, narrowly lanceolate to subulate, straight, 1.8-3.8(-4.8) mm.

Ranunculus orthorhynchus is a species of buttercup known by the common name straightbeak buttercup. It is native to western North America from Alaska to California to Utah, where it grows in moist areas in many types of habitat, including meadows and marshes.