Pteronia incana involucre

Pteronia incana involucral bract shapes change progressively from the short, broad outer ones to the long and oblong inner ones. The white at the rounded bract tips probably indicates a ciliate or finely short-haired fringe.

The exposed parts of inner bracts allow glimpses of the tubular lower parts of the florets inside, indicating transparency or at least translucency of these bracts.

Leaf elongation counteracts hair density, allowing more green skin to be shown among the otherwise white velvet, probably benefiting photosynthesis (Vlok and Schutte-Vlok, 2015; Manning, 2007; Manning and Goldblatt, 1997; iNaturalist).