Family: Linaceae

When New Zealanders think of flax, this low-growing shrub with pretty white flowers is not the plant that springs to mind. However, our sole species of Linum is closely related to the true flax, Linum usitatissimum – the source of both linen and flaxseed.

I must admit that when I first reflected upon the use of this plant for textiles, I was mystified as to how one would extract fibres from it – with its small leaves and delicate appearance. However, the answer is to be found in the stems of the true flax, which yield the long fibres that are worked into a range of materials (including linen, twine and paper). The plants that we know as flax within New Zealand (Phormium spp.) were named after Linum usitatissimum – due to the fact that they yield useful fibres, rather than any visual similarity (which clearly does not exist).

Linum monogynum

Rauhuia; New Zealand linen flax

With its wispy, refined appearance, rauhuia seems at odds with the ferocity of the coastal environments in which it is mostly found. Its small bluish leaves just don’t look up to receiving the attentions of a salty gale, but nevertheless, this compact shrub takes its place as one of the many beautiful details that adorn cliffs and rocky ground of our coastlines.

The most prolific populations that I have viewed of ths species were along the Marlborough coastline, where L. monogynum grew alongside Marlborough rock daisies (Pachystegia spp.) and emerged from cliffs and grassy banks (as shown in the image below). Linum monogynum produces copious quantities of pure white flowers from late spring through to the end of summer, making it one of our most attractive coastal flowering plants and an excellent garden subject.

Rauhuia is an easy plant to grow, but requires some thought in its placement, due to its relatively short lifespan. It is ideally suited as a gap filler or a floral highlight, rather than as a structural shrub. Like its fellow coastal native species, Hibiscus richardsonii, Senecio radiolatus and Senecio sterquilinus, this plant also has significant potential for annual bedding flower displays.

Plants seed themselves freely within suitable conditions, providing gardeners with a continuing supply of material for following seasons. After plants have set seed, it is best to trim the longer stems, to encourage a compact form.

There is a pronounced difference between typical forms of L. monogynum and plants from the Chatham Islands, the latter exhibiting a more robust growth habit. Flowers of the Chatham Islands form (which is frequently treated as a separate variety) also commonly bear a distinctive pale blue colouration to their flowers. However, there exists variation amongst mainland forms of the species, which might also warrant horticultural selection (especially where significant local forms may be utilised within an area).