Colors

Data mode

Account

Login
Sign up

Support FSUS...

We've finished our 2024 fundraiser. Many thanks to those who have given! It's not too late to support us (click here)...

Click the number at the start of a key lead to highlight both that lead and its corresponding lead. Click again to show only the two highlighted leads. Click a third time to return to the full key with the selected leads still highlighted.

Key to Potentilla

Copy permalink to share

1 Leaves pinnately compound, with (5-) 7-21 (-31) leaflets.
  2 Leaves with (5-) 7-21 (-31) leaflets; flowers solitary, on naked, axillary pedicels; lower leaf surface silvery-white, densely appressed-hairy
  2 Leaves with 5-9 leaflets; flowers (10-) 20-100 (or more) in a cyme or raceme; lower leaf surface green, glabrate or sparsely hairy; [section Rivales]
1 Leaves palmately compound, with 3-9 leaflets.
    3 Flowers solitary, on naked, axillary pedicels; leaves either palmately 3-5-foliolate or pinnately (5-) 7-21 (-31)-foliolate.
      4 Leaves 3-foliolate; fruit strawberry-like, fleshy and red, consisting of an expanded fleshy receptacle bearing superficial achenes; [formerly genus Duchesnea]
      4 Leaves primarily 5-foliolate on a plant (some poorly developed leaves may be 3-4-foliolate); fruit a head of achenes, dry; [section Potentilla].
        5 Sepals 4; petals 4; stems branching when well-developed; leaves with 3-5 leaflets; [rare waif]
        5 Sepals 5; petals 5; stems not branching; leaves with 5 leaflets (fewer only on smaller or poorly developed leaves); [collectively common and widespread].
          6 Plants lacking rhizomes; petals (6-) 8-12 mm long; anthers 1.3-2.0 mm long
          6 Plants with horizontal rhizomes; petals 4-10 mm long; anthers 0.6-1.0 mm long.
             7 Terminal leaflet (of well-developed leaves) toothed for < ½ its length, with 2-7 teeth per leaflet side; terminal leaflet usually < 2× as long as wide; lowest flower produced from the axil of the 1st stem leaf above the plant base, typically with only 1 leaf and pedicel at each subsequent node; plants often flowering on short stolons obscured by basal leaves; stem usually prostrate from the beginning, 0.3-0.8 mm in diameter
             7 Terminal leaflet (of well-developed leaves) toothed for > ½ its length, with 4-8 (-13) teeth per leaflet side; terminal leaflet usually > 2× as long as wide; lowest flower produced from the axil of the 2nd stem leaf above the plant base, typically with 2 leaves and 1 pedicel at each subsequent node; plants only flowering on elongating stolons; stem usually erect initially, 0.9-1.4 mm in diameter
    3 Flowers in terminal cymes; leaves palmately 3-9-foliolate.
               8 Leaves 3-foliolate (sometimes with some leaves 5-foliolate); [section Rivales].
                 9 Hairs of the stem stiff, tubercle-based, to 3 mm long; petals (2-) 3-5 mm long; stamens (15-) 20; achenes usually ridged, tan or brown, 0.8-1.3 mm long
                 9 Hairs of the stem weak, not tubercle-based, to 1.5 mm long; petals 1.5-2 mm long; stamens (5-) 10 (-15); achenes smooth, white or yellowish, 0.7-0.9 mm long
               8 Leaves 5-9-foliolate.
                   10 Leaves (5-) 7-9-foliolate; petals 8-15 mm long, pale (sulfur) yellow; [section Rectae]
                   10 Leaves 5 (-7)-foliolate; petals 3-7 (-8) mm long, medium yellow; [section Terminales].
                     11 Leaves pubescent beneath, the green surface not concealed; petals 4-5 mm long
                     11 Leaves densely tomentose beneath, the surface concealed; petals either 2.5-4 mm long or 5-7 (-8) mm long.
                       12 Pubescence of the stem and veins of the leaf undersurface tomentose only; lower leaf surface silvery-white tomentose; leaves revolute; petals 2.5-4 mm long
                       12 Pubescence of the stem and veins of the leaf undersurface tomentose and also with long, spreading hairs; lower leaf surface somewhat to strongly grayish-tomentose; leaves not revolute; petals 5-7 (-8) mm long