1. Leaves undivided (though regularly toothed).

T. balsamita

1. Leaves pinnatifid or bipinnatifid.

2. Rays absent or yellow.

3. Heads (12-) 13-19 (-22) mm broad; leaves ± hairy.

T. bipinnatum

3. Heads 5-10 mm broad; leaves glabrous or nearly so.

T. vulgare

2. Rays present, white or pink.

4. Rays white, 4 - 8 mm long; heads numerous per stem (except in depauperate plants)

T. parthenium

4. Rays bright pink, fading to a dull pale pink, ca. 12 - 20 mm long; heads few (1-3) per stem

T. coccineum