Argyranthemum, commonly known as marguerite daisy or dill daisy, is a genus of flowering plants in the family Asteraceae (daisy family), order Asterales. The genus comprises roughly 24 species of subshrubby perennials and shrubs, all endemic to the Macaronesian archipelagos — the Canary Islands, Savage Islands, and Madeira — where they occupy a range of habitats from coastal cliffs to mountain scrub.
Plants in this genus produce characteristic daisy-like flower heads with white, yellow, or pink ray florets surrounding a yellow disc, borne on branching stems with pinnately divided or finely cut foliage. The genus has historically been subsumed within Chrysanthemum, but is now treated as distinct based on its restricted island distribution and consistent morphological characters.
Argyranthemum species are ecologically significant as endemic island plants with restricted ranges, and several species are considered threatened. The larval stage of the leaf-mining moth Bucculatrix chrysanthemella is recorded feeding on Argyranthemum frutescens.
In cultivation, hybrids of Argyranthemum species (sometimes crossed with related genera) are among the most popular summer ornamentals in temperate gardens, sold widely as bedding and container plants for their prolific, long-lasting daisy blooms in shades of white, pink, yellow, and purple.
Etymology
The name Argyranthemum derives from the Greek argyros (silver) and anthemon (flower), alluding to the silvery-white ray florets characteristic of many species in the genus.
Distribution
The genus is strictly endemic to Macaronesia, with all naturally occurring species confined to the Canary Islands, the Savage Islands (Ilhas Selvagens), and Madeira. Individual species are often further restricted to single islands or small island groups within this range.
Cultivation
Hybrids of Argyranthemum species are widely sold as ornamental plants for summer bedding and container gardening. These cultivars produce prolific single or double daisy-like flowers in white, pink, yellow, and purple throughout the summer season. In temperate climates such as the UK they are generally half-hardy and are grown from seed or cuttings, or purchased as young plants to be set out after the last frost.
Conservation
All Argyranthemum species are island endemics with inherently restricted natural ranges on the Canary Islands, Madeira, and the Savage Islands, making them vulnerable to habitat loss, invasive species, and climate change. Several species are monitored under regional conservation frameworks applicable to Canarian and Madeiran endemic flora.
