The effects of Bolandia pinnatifida disc floret elongation and maturation are illustrated by the two flowerheads in the foreground.
The younger head has floret buds still shorter than the pointed, maroon-brown bracts around them. Not quite a bud itself any longer, the head has straightened the involucre by now from incurving, the bracts forced outwards into a cylinder by the elongating bunch of floret buds. Only the bract tips still curve in.
In the second head the involucre has been overwhelmed by the hemisphere of creamy white, open florets that have taken over and pushed outwards, wider than the rim of the cup below (Bond and Goldblatt, 1984; iNaturalist).