The leaves have nectaries at the tips; these attract ants, which play a role in the distribution of seed.

Like most other Adenanthos species, but unusually for Proteaceae, the flowers of common woollybush are not large and showy, but are rather small, dull, and hidden within the foliage.

Adenanthos cygnorum was first collected by the English botanist and plant-collector Allan Cunningham in 1818 at the Swan River, Western Australia.

The specific name cygnorum, from the Latin cygnus meaning swan, refers to the type locality.

The latter is a prostrate, mat-forming shrub; it is rare and poorly known, and some populations are under threat, but is not currently considered endangered.