Linum monogynum

{{Short description|Species of flowering plant}}

{{Use New Zealand English|date=October 2024}}

{{Speciesbox

|image = Linum monogynum var. chathamica kz04.jpg

|image_caption = Linum monogynum var. chathamicum

|genus = Linum

|species = monogynum

|authority = G.Forst.

}}

Linum monogynum, the rauhuia or New Zealand linen flax, is a species of flowering plant in the family Linaceae, which is endemic to New Zealand. It is a low-growing short-lived perennial or woody subshrub, growing up to {{convert|16|in|cm|abbr=on}} tall. Its spear-shaped, leathery-gray to green leaves are 0.2–1 inches (5–25 mm) long. Its pretty white flowers are up to {{convert|1|in|cm|abbr=on}} in diameter, and have five overlapping petals. It is monoecious, having both male and female organs on one plant (hence the Latin specific epithet monogynum, literally "single wife").{{cite web | url = https://pfaf.org/user/Plant.aspx?LatinName=Linum+monogynum

| title = Linum monogynum | publisher = Plants for a Future | access-date = 10 November 2019}}

Separate populations on Chatham Island are more robust with blue-white flowers, and may be referred to as L. monogynum var. chathamicum. There may also be variations amongst the mainland populations.{{cite web | url = http://nzpcn.org.nz/flora_details.aspx?ID=939 | title = Linum monogynum var. monogynum | publisher = New Zealand Plant Conservation Network | access-date = 10 November 2019}}

This tough compact plant is well able to cope with the harsh conditions of New Zealand's coasts, often with gale-force salt-laden winds. It is a close relative to the true flax of the Northern Hemisphere, Linum usitatissimum, but is not closely related to the much better-known plants called New Zealand flax (species in the genus Phormium).{{cite web | url = http://www.o2landscapes.com/pages/pp-linum.php | title = Plant Profiles - Linum | publisher = O2 Landscapes | access-date = 10 November 2019}}