Linum catharticum
Common names
purging flax
Family
Linaceae
Flora category
Vascular – Exotic
Structural class
Herbs - Dicotyledons other than Composites
NVS code
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
LINCAT
Conservation status
Not applicable
Simplified description
Slender, delicate herb, with narrow paired leaves, up to 1 cm long, well separated up the thin stems, with an open branched flowerhead with small (1 cm across) white flowers.
Distribution
Locally common throughout.
Habitat
Wet grassland, dunes, margins of waterbodies, often in areas that are seasonally dry.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
FAC: Facultative
Commonly occurs as either a hydrophyte or non-hydrophyte (non-wetlands).
Detailed description
Slender biennial herb up to 30-(35) cm high. Stems glabrous, simple to much-branched at base. Stem lvs always opposite, glabrous, oblong to narrowly elliptic-obovate, usually obovate at base of stem, obtuse to acute, 1-veined, entire, (3)-5-12-(15) mm long; lvs subtending infl.-branches single or paired, similar to stem lvs but shorter, narrower and sometimes acuminate. Infl. of few to numerous fls in a diffuse compound dichasium; sepals elliptic, acuminate, glandular, ciliate, 2-3 mm long, slightly < or ± = to capsule; petals white, about 2× as long as sepals, 3.5-5 mm long; styles free to base. Capsule glabrous, globose, dehiscent, 2-3 mm diam.; seeds boat-shaped, shiny light brown, c. 1 mm long.
Similar taxa
No other Linum in New Zealand is as delicate or has opposite leaves.
Flowering
October to April
Flower colours
White, Yellow
Fruiting
Summer and autumn
Life cycle
Seed dispersed by water or contaminated machinery.
Year naturalised
1896
Origin
Europe, western Asia and North Africa
Reason for introduction
Unknown, seed or soil contaminant.
Control techniques
Not controlled in New Zealand.
Etymology
linum: Flax
Attribution
Prepared by Paul Champion and Deborah Hofstra (NIWA). Features description from Webb et al., (1988).
References and further reading
Webb, C.J.; Sykes, W.R.; Garnock-Jones, P.J. (1988). Flora of New Zealand Volume 4: Naturalised pteridophytes, gymnosperms, dicotyledons. Botany Division, DSIR, Christchurch.
Johnson PN, Brooke PA (1989). Wetland plants in New Zealand. DSIR Field Guide, DSIR Publishing, Wellington. 319pp.