Phormium is a genus of two species of herbaceous perennial monocots in the family Asphodelaceae (order Poales), native to New Zealand and its outlying Norfolk Island. The genus is placed in subfamily Hemerocallidoideae alongside daylilies (Hemerocallis), a relationship confirmed by the Angiosperm Phylogeny Group; earlier classifications placed it in Agavaceae.
The plants are recognised by their bold, strap-like foliage: tough, sword-shaped leaves that can reach 3 metres (10 ft) in length and up to 125 mm (5 in) wide. Wild plants are typically dark green, though cultivated forms span a spectrum from pale lime through pink to deep russet bronze, including numerous variegated selections striped in green, red, bronze, pink, and yellow. Rigid flower stalks rise up to 5 metres (16 ft) above the foliage, bearing clumps of curving, tubular flowers that turn bright red at maturity and produce abundant nectar. In New Zealand this draws nectar-feeding birds such as the tūī; wind dispersal carries hundreds of seeds per pod once pollination is complete.
The two species are Phormium tenax (harakeke in Māori), native to New Zealand and Norfolk Island, and Phormium colensoi (wharariki), endemic to New Zealand. Both are widely known as New Zealand flax or flax lily, though they are unrelated to Northern Hemisphere flax (Linum usitatissimum). The fibrous leaves have been central to Māori material culture and the colonial fibre industry, and both species are now grown as ornamentals across temperate regions worldwide. Over 75 named cultivars were listed in the Royal Horticultural Society Plant Finder by 2005–2006, and several hold the RHS Award of Garden Merit.
Etymology
The genus name Phormium derives from the Ancient Greek word for "basket," reflecting the traditional use of the plant's fibrous leaves in weaving. The type species epithet tenax is a Latin adjective meaning "holding fast" or "tenacious," alluding to the toughness of the leaf fibres. The genus was formally established in 1775 by Johann Reinhold Forster and Georg Forster from specimens collected during Captain James Cook's second voyage aboard HMS Resolution.
Distribution
Phormium tenax occurs naturally in New Zealand and Norfolk Island, while P. colensoi is endemic to New Zealand. Both species grow mainly in swamps and low-lying areas but tolerate a variety of habitats. Since the nineteenth century both have been widely introduced to temperate regions worldwide, cultivated both as ornamental garden plants and as a source of commercial leaf fibre.
Ecology
Phormium species grow mainly in swamps and low-lying areas, though they tolerate a range of wetland and open habitats. The flowers produce unusually large quantities of nectar, attracting nectar-feeding birds — most notably the tūī — as well as insects; this makes the plants important components of New Zealand native bird–plant mutualistic networks. After pollination, each seedpod contains hundreds of seeds that are dispersed by wind.
Cultivation
The two species interbreed readily, and there is considerable regional variation in Phormium colensoi; where the two co-occur, local introgression occurs. Breeding work from the 1920s onward showed that ploidy influences cultivar characteristics. Commercial interest expanded markedly in the late twentieth century: by 2005–2006 the RHS Plant Finder listed 75 cultivars. Several cultivars have received the RHS Award of Garden Merit for performance in UK gardens. The highly regarded sport 'Ngaro' was isolated from the Moutoa swamp near Foxton, New Zealand.
Cultural Uses
Phormium has played a central role in the culture, history, and economy of New Zealand. The Māori people used the long, tough leaf fibres of harakeke (P. tenax) extensively for weaving kete (baskets), whāriki (floor mats), kākahu (garments), and cordage. The fibres were also exploited commercially as an export crop during the colonial era. Both species continue to hold deep cultural significance in Māori tradition, and harakeke is frequently used as a symbol of family and community in Māori philosophy.
