Petasites

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  P. frigidus

  1a. Capitula usually with marginal ray flowers, the rays 0.1–6.3 mm long; leaf blades prominently ± palmately lobed with deep sinuses, the sinuses extending more than 50% 
of the distance from the margin to the leaf midrib [Fig. 442]
• See list of 2 species in 1b
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  1b. Capitula without marginal ray flowers [Fig. 443]; leaf blades ± dentate, the lobes absent or obscure, the sinuses (when present) extending much less than 50% of the distance from the margin to the leaf midrib
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    P. japonicus

    2a. Disk corollas cream-white; bracts of scape usually green, the one subtending the lowermost branch of the capitulescence 17–40 mm wide; leaf blades with (4–) 5 (–6) pairs of lateral veins emerging along the inner margins of the basal sinus
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    P. hybridus

    2b. Disk corollas largely purple; bracts of scape usually purple or purple-tinged, the one subtending the lowermost branch of the capitulescence 5–16 mm wide; leaf blades with 2–5 pairs of lateral veins emerging along the inner margins of the basal sinus

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 Show photos of:   Each photo represents one species in this genus.