A Protea glabra flowerhead may allow florets on one side, favoured by the sun or some other factor to open first. Protea flowerheads, also P. glabra ones, usually start off by opening peripheral perianths, working towards the last ones in the centre.

Pollinators benefit from a protracted feeding period in one spot as famine may arrive suddenly when open flowers disappear. Extended blooming among their favourites species save them energy of scouting the countryside in search of the next meal. All sequential blooming patterns extend the pollen and nectar availability intervals, irrespective of the starting point. The centrist moderates may fare as well as the biased extremists, unless the one sequence manifests faster than the other.

The P. glabra perianth reaches a length from 3,5 cm to 5 cm. The style also becomes 5 cm but is longer than the perianth when the 1 cm pollen presenter at its tip is added.

P. glabra flowerheads are sweetly scented, a feature unusual for the Protea genus (Rourke, 1980; Manning, 2007; Coates Palgrave, 2002; iNaturalist).