Hibbertia (Andrews, 1800), commonly known as guinea flowers or button flowers, is a genus of roughly 400 flowering plant species in the family Dilleniaceae. The genus is predominantly Australian, with the overwhelming majority of species endemic to that continent, while a smaller number extend to New Guinea, New Caledonia, Fiji, and Madagascar.
Members of the genus are mostly shrubs, ranging from low prostrate mat-formers to upright bushes, with a minority of species adopting a climbing or scrambling habit. The leaves are alternate, sessile, and borne on short branches with smooth margins. Flowers are characteristically five-petalled and most often bright yellow — a vivid hue that inspired the common name "guinea flower," evoking the gold guinea coin — though orange, red, pink, and white variants are also known. Stamens are grouped into three to five bundles, and the gynoecium comprises two to five free carpels, each capable of producing up to six ovules. Fruits are follicles, and the seeds typically bear a fleshy aril.
The genus is divided into several subgenera, including Hibbertia, Adrastaea, Pachynema, and Hemistemma, reflecting morphological variation across the group. GBIF records 451 descendant taxa at all ranks. The Australian Plant Census (APC) serves as the current nomenclatural authority for the genus in Australia, where species are distributed across all mainland states and Tasmania, from coastal habitats through inland tablelands and mountain ranges.
Etymology
The genus name Hibbertia was coined by the botanist Henry Cranke Andrews in 1800, honouring George Hibbert, an English merchant and patron of botany. Andrews published the name in The Botanist's Repository for New, and Rare Plants (T. 126, 472). The widespread common name "guinea flower" alludes to the bright yellow colour and rounded shape of the flowers, which were likened to the gold guinea coin.
Distribution
Hibbertia is overwhelmingly an Australasian genus. Of approximately 400 species, the vast majority are native to Australia, where the genus occurs in every state — Western Australia, Queensland, New South Wales, South Australia, Victoria, and Tasmania — across a wide range of environments from coastal heathlands to inland tablelands and montane ranges. A small number of species extend beyond Australia to New Guinea, New Caledonia, Fiji, and Madagascar.
Taxonomy
Hibbertia Andrews (1800) is the type and largest genus of the family Dilleniaceae, placed in the order Dilleniales within the eudicot angiosperms (class Magnoliopsida, phylum Tracheophyta). GBIF recognises the name as accepted, with usage key 3234609 and 451 descendant taxa at all ranks. The genus encompasses several subgenera — Hibbertia, Adrastaea, Pachynema, and Hemistemma — that capture major morphological groupings. The Australian Plant Census (APC) is the primary nomenclatural authority for Australian members. Numerous historical synonyms attest to extensive taxonomic revision of the genus since its original description.
