Geraldton wax (Chamelaucium uncinatum) flowers—looking beneath the epidermis

Abstract

Chamelaucium uncinatum Schauer. (Geraldton wax) is well known as a garden and cut-flower species in Western Australia. The location of pigmented cells and the shape of the epidermal cells that interact with incident light can affect flower colour. This study examined the location of pigments within petals of three C. uncinatum cultivars, 'Purple Pride', 'CWA Pink' and 'Alba', which represent the range of colours found in this species. The white cultivar ('Alba') lacked coloured pigments in the petals while the pink ('CWA Pink') and purple ('Purple Pride') cultivars had pigmented vacuoles in petal epidermal and mesophyll cells. A waxy coating was present on petal epidermal cells of all cultivars and cells of the adaxial epidermis were found to be conical. Patterns in petals of 'CWA Pink' and 'Purple Pride' were due to cultivar-specific location of pigments.