New Zealand Flax (the Phormium sp. ) are large strap-leafed evergreen perennials that for many years were believed to be members of the in the Agave family (Agavaceae).

Recently taconomy created the family Phormiaceae into which Phormium and Dianella have been placed. There are two species in the genus:

• Phormium tenax, the Coastal Flax, the larger and more common plant; its long strap leaves in shades of green, bronze and maroon.
• Phormium cookianum, the Mountain Flax, (P. coloensoi), a smaller, more graceful plant that has just lately been gaining popularity as a garden plant.

Flax

The common name 'flax' is applied to several very different plants. The fibrous nature of 'flax' plants and their usage for items such as rope and clothing is what links such unrelated plants as the 'true' or Asian Flax (Linum usitatissimun) and New Zealand Flax (Phormium sp.) .

Flax plant on the island

True Flax, and its ornamental relative, Yellow Flax (Reinwardia indica), are both dicotyledons in the Linaceae, or Flax family; the New Zealand Flax are monocotyledons that until recently were placed in the Agavaceae, or Agave Family.

On Captain Cook's second expedition to the South Pacific in 1773 Phormium tenax was first described, but it was the early traders who came to New Zealand who noted the similarity between its fibre and that of the true flax. These traders observed the usage of Phormium by the Maori, the Polynesian people who had settled in New Zealand. The Maori tribes used the name 'harakeke' for Phormium tenax and 'wharariki' for the smaller Mountain Flax, Phormium cookianum .

From both of these plants the Maori used the leaves for weaving baskets, mats, head-bands, and other items. They used the fibres of the leaves for making clothing, fishing nets, and ropes. The roots yielded the material to make medicine and nectar was obtained from the flowers as was pollen to make face powder. Even the spent flower stalks were used to make rafts to cross rivers and lakes.

On St Helena the plant was used to make sisal, but this use declined with the introduction of man-made fibre ropes later in the 20th century.

Phormium

Donkeys carrying flax

The use of the New Zealand Flax leaves in the making of baskets gives the scientific name Phormium , which translates from Greek as basket.

While New Zealand botanists insist that Phormium cookianum is the valid name for the mountain flax, many recent texts, including Sunset's Western Garden Book and The Royal Horticultural Encyclopedia of Plants, have adopted the synonym P. colensoi as the current name.

Climatic Tolerance

As a general rule the Phormium tenax is usually tolerant to extremely hot or cold temperatures, prolonged dry conditions and heavy soil. Plants can survive extensive periods without water; and have been known to survive an entire summer without rain. Phormium plants suffer from few other maladies.

Flowering

New Zealand Flax is not renowned for its flowers, as it is the colorful foliage or striking form that is of primary interest. However, Flax will often flower in the garden in late spring or early summer, and are not only showy but also attract nectar seeking birds.

The flowers on Phormium tenax and many of the hybrids are orange-red and held upright on a tall stalk above the foliage. Phormium cookianum, and the hybrids more closely aligned with it, have greenish-yellow flowers that are held horizontally on an arching flower stalk.

The fruit that follows is also quite different: P. tenax has its woody bean-like fruit held upright and P. cookianum has twisted dangling fruit. The flowers and dried fruit of both types are useful in large flower arrangements.