Erica margaritacea bears white or sometimes pale pink flowers in fours or umbel-shaped clusters. The peduncles of 2 mm to 4 mm bear small, leaf-like bracts above their middle parts. The four, narrow sepals with toothed margins do not quite adhere to the corolla base, about half as long as the corolla.
The urn-shaped corolla is 4 mm long, narrowing slightly at its mouth before the four shallowly rounded lobes angle out slightly. The dark anthers are included, visible in the wide mouth. The style is longer, tipped with the dark stigma that is usually shortly exserted.
The specific name, margaritacea, is derived from the word margarita that besides being a name means pearl in old Persian and Sanskrit, referring to the small, pearl-shaped corollas, or maybe to the predominantly white flower colour.
Flowering happens from before midspring to after midautumn (Baker and Oliver, 1967; Bond and Goldblatt, 1984; iNaturalist).