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Tanacetum
See list of 3 species in this genusReference: Watson (2006).
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1a. Rays 4–8 mm long, white; cypsela body with 7–10 ribs
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1b. Rays absent or up to 4 mm long and yellow; cypsela body with 5 ribs
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2a. Leaf blades glabrous or nearly so; disk 5–10 mm wide; capitulescence with (10–) 20–70 (–100) capitula; rays absent
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2b. Leaf blades villous; disk 10–18 mm wide; capitulescence with 1–15 (–30) capitula [Fig. 470]; rays present, 1–3 (–4) mm long
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Each photo represents one species in this genus.