Abstract:
The name Petalidium ovatum is reinstated and an amplified description is provided for a species of Petalidium confined to
Namibia. Petalidium ovatum used to be treated as a synonym of the widespread P. englerianum, but morphological characters
support the reinstatement. Petalidium ovatum is a range-restricted species, only known from the Khorixas-Bergsig
area in the Kaokoveld Centre of Endemism, northwestern Namibia, where it grows on arid hillsides and along ephemeral
riverbeds and drainage lines. Diagnostic characters for P. ovatum include the pale grey, often almost white, appearance of the
plants, vegetative parts with a dense white indumentum of both stellate and dendritic trichomes, flowers borne in short fewflowered
dichasia, bracts oblanceolate with apices acute or obtuse, and bracteoles widely ovate. The flowers of P. ovatum are
distinctive in having the anterior corolla lobe partly or completely yellow, the others burgundy, and with the two upper lobes
connate towards the base for almost half their length. A comparison of some of the more prominent morphological features
to differentiate Petalidium ovatum from P. englerianum, its morphologically most similar relative, is provided. Based on
IUCN Red List categories and criteria, a conservation assessment of Least Concern (LC) is recommended for the reinstated
species.
