Astelia is a genus of rhizomatous, tufted perennial herbs in the family Asteliaceae (order Asparagales). Plants typically form dense clumps with short, often hidden stems bearing leaves arranged in three ranks. The leaves are linear to sword-shaped (ensiform), and the entire plant is covered in a characteristic scale-like silvery indumentum — a felt-like coating of flattened hairs that gives many species a silver or bronze sheen.
The genus is dioecious, with male and female flowers borne on separate plants. Flowers are small, arranged in terminal panicles, and give rise to berries containing glossy black seeds. Growth habit ranges from strictly terrestrial — in bogs, alpine grasslands, and forest understories — to epiphytic, with some species perching on the branches and trunks of large trees such as the kauri (Agathis australis) in New Zealand.
Astelia encompasses around 25–45 species (estimates vary by authority), distributed across remote islands of the Pacific, Indian, and South Atlantic Oceans, with a major centre of diversity in New Zealand, where 15 endemic species are recognized. The genus also extends to Australia, New Guinea, Hawaii, Samoa, Fiji, Réunion, Mauritius, the Falkland Islands, and Tierra del Fuego. Robert Brown formally published the genus in 1810 in his Prodromus Florae Novae Hollandiae et Insulae Van Diemen (p. 291), based on collections made by Joseph Banks and Daniel Solander.
Taxonomy
Astelia Banks & Sol. ex R.Br. was formally described by Robert Brown in Prodromus Florae Novae Hollandiae et Insulae Van Diemen (page 291, 1810), based on earlier collections by Joseph Banks and Daniel Solander. It belongs to the family Asteliaceae within the order Asparagales (monocots), and sits in class Liliopsida, phylum Tracheophyta.
Three genera have historically been treated as synonyms: Funckia Willd., Hamelinia A.Rich., and Collospermum Skottsb. The GBIF backbone lists 45 descendants under the genus key, though the accepted species count varies between checklists. The vernacular name "Pineapplegrass" is registered in GBIF for the genus.
Distribution
Astelia has a distinctive Southern Hemisphere and Pacific island distribution, centred on New Zealand, which harbours 15 endemic species. Beyond New Zealand the genus occurs in Australia (including alpine areas of Victoria and Mount Kosciuszko), New Guinea, and numerous island groups: Hawaii, Samoa, Fiji, Vanuatu, New Caledonia, and French Polynesia (Tahiti, Raiatea, and the Marquesas Islands) in the Pacific; Réunion and Mauritius in the Indian Ocean; and the Falkland Islands, Tierra del Fuego, and Patagonia at the southernmost tip of South America. This disjunct pattern — spanning remote oceanic islands and southern continental margins — is consistent with long-distance dispersal, likely via frugivorous birds attracted to the fleshy, black-seeded berries.
Ecology
Species of Astelia occupy a wide range of habitats, from lowland forests and swamps to low alpine and subalpine vegetation. In New Zealand, several species are notable epiphytes, colonising the boughs and trunks of large trees — including the kauri (Agathis australis) in stands such as Trounson Kauri Park — where they gather organic debris in their leaf bases in a manner convergent with bromeliads. Terrestrial species grow in bogs, tussock grasslands, and montane scrub. The dioecious breeding system and bird-dispersed berries are ecologically significant traits shared across the genus.
Cultural uses
In New Zealand, Astelia species are known by the Maori names Mauri, Mauri kura, and Whara. The large-leaved species such as Astelia fragrans (Kakaha or Bush Flax) and Astelia banksii have leaves that were historically used by Maori for plaiting and weaving, serving as a substitute for harakeke (New Zealand flax) in some regions. The common name "Bush Flax" reflects this traditional use.
