Polyarrhena is a genus of low, branching shrublets that is assigned to the daisy family (Compositae or Asteraceae).

Like in almost all Asteraceae, the individual flowers are 5-merous, small and clustered in typical heads, and which are surrounded by an involucre of in this case three whorls of bracts.

These florets sit on a common base (or receptacle) and are not individually subtended by a bract (or palea).

In the Dictionnaire des Sciences Naturelles, volume 56, that was published in 1828, French Asteraceae specialist Henri Cassini erected the genus Polyarrhena, and named the type species Polyarrhena reflexa, that was based on Aster reflexus.

Christian Friedrich Lessing in 1832 assigned P. reflexa to his new genus Elphegea, with two other species that have sterile disc florets, E. bergeriana (now Felicia bergeriana) and E. ciliata (now Zyrphelis taxifolia), Nees von Esenbeck in the following year retained Polyarrhena, but Augustin Pyramus de Candolle included P. reflexa in Felicia in 1835, while Irish botanist William Henry Harvey in 1865 reenlisted the species under Aster.

The dull brown to yellowish, indehiscent one-seeded fruits (called cypselas) have no short hairs over their surface, have two vascular bundles along their edges, are crowned by one row of bone-colored, soft hairs (or pappus)with short teeth along their length that easily detach.

Polyarrhena imbricata is an ascending or erect low shrublet of about 15 cm (5.9 in) high with the outer whorl of involucral bracts over the entire surface consistently hairy, the leaves pressed to the stem, overlapping and the heads sit on up to 6 cm (2.4 in) long leafless peduncles.

[1] The species of Polyarrhena have a strong likeness to those of Felicia section Anhebecarpaea, in particular P. reflexa to F. echinata, P. imbricata to F. nordenstamii and P. stricta to F.