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Key to Ranunculus, Key D: subgenus Ranunculus; sections Polyanthemos, Ranunculus, and Echinella
..2 Petals (3-) 4-12 mm long; receptacles pubescent.
....3 Achenes bodies 1.5-3 mm long, 30-60 per head; achene beak ca. 0.5 mm long; achene with conical protuberances or short spines, to 0.16 mm long; achene beak 0.1-0.5 mm long; basal leaves compound; [section Polyanthemos].
......4 Achene with a few conical protuberances; petals 5-12 mm long; plant sparsely to densely hirsute; achenes 30-40 per head
....3 Achenes 2.5-5 mm long, 4-20 per head; achene beak 1.5-3.0 mm long (or 0.8-1 mm long in R. marginatus); achene conspicuously spiny, the longer spines mostly 0.30-0.85 mm long (or only ca. 0.2 mm long in R. marginatus); basal leaves simple (but deeply lobed) or compound.
........5 Achenes 4-9 per head, in a single whorl; achene margins spiny, as also the faces; beak of the achene 2.5-3 mm long; [section Echinella]
........5 Achenes 10-20 per head, in several whorls; achene margins smooth, the spines restricted to the faces; beak of the achene 1.5-2.5 mm long; [section Polyanthemos].
..........6 Achene faces with short protuberances ca. 0.2 mm long; achene beak 0.8-1.0 mm long; peduncle usually longer than the subtending leaf