Chaerophyllum colensoi var. delicatulum
Oreomyrrhis colensoi var. delicatula Allan
Vascular – Native
Herbs - Dicotyledons other than Composites
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.
2n = 14
Current conservation status
The threat classification status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley. Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – a suggested threat classification status has not been assessed by the NZTCS panel.
2018 | Threatened – Nationally Endangered
Previous conservation statuses
2017 | Threatened – Nationally Endangered | Qualifiers: DP, EF, RR
2009 | Threatened – Nationally Critical | Qualifiers: CD, DP
2004 | Threatened – Nationally Endangered
Endemic to New Zealand, where it is found in the North and South Islands, from the Hauhangaroa Range to Southland. It has a mainly easterly distribution in the South Island.
A plant of ephemeral wetlands, subalpine flushes, and tarn margins. Strictly subalpine in the North Island but descending to lower montane habitats in the South Island.
Diminutive, shortly rhizomatous, perennial herb arising from stout tap root, plants forming circular mats up to 50 x 50 mm (usually much less). Petioles filiform, brown-green, yellow-green to white, 10-20 mm long. Leaves radical, spreading up to 20 mm long, dark green, red-green to brown-green 1(-2) pinnate with 4-6(8) distant pairs of primary pinnae. Both leaf surfaces sparsely covered in fine hairs, lamina margin particularly so, pinnae of equal length, or broader toward middle and decreasing in length toward distal and proximal ends, linear, narrowly lanceolate to lanceolate, apex narrowly acute, deeply toothed, entire, or with prominent secondary pinnae in the basal 1-3 primary pinnae pairs. Peduncles 1-5(-15), filiform, stout or slender up to 30 mm long, decumbent to sub-erect, spreading. Involucre of 5-8 ovate-oblong bracts; bracts up to 5 mm long, pale green to yellow-green, entire. Pedicels at flowering subsessile, elongating in fruit up to 6 mm. Flowers 3-8, 1.5-2 mm diameter. Petals 3-5, 0.3-0.5 x 0.3-0.5 mm, ovate, cream. Mericarps 1.5-2 x 0.6-1.3 mm, narrow-ovate to ovate, glabrous. Ribs 3-5.
Oreomyrrhis colensoi var. delicatula differs from other members of the O. colensoi Hook.f. complex by its smaller size, narrower, less divided leaves, narrower, sharply pointed pinnae (leaflets), and generally by the hairless fruits. However, the distinction is not always clear and intermediates are common in some parts of the country.
October - February
December - May
Easy from fresh seed and division of whole plants. Difficult to maintain for any length of time. Plants are best grown in a permnantly moist soil, within a pot in full sun. Will not tolerate competition from taller plants.
The open wetland turf and tarn margin habitats frequented by O. colensoi var. delicatula are extremely vulnerable to invasion by faster growing and taller weeds. In many parts of the North Island this species has gone extinct because of weed competition. O. colensoi var. delicatula, along with many other wetland marginal turf plants is also extremely vulnerable to changes in the hydrology of the wetlands they require. In many places these are now drying out too early, because of changes in adjacent land use management, so increasing their vulnerability to weed species invading and becoming permanently established.
chaerophyllum: From the Greek chairo ‘to please’ and phyllon ‘leaf’
colensoi: Named after William Colenso (7 November 1811 - 10 February 1899) who was a Cornish Christian missionary to New Zealand, and also a printer, botanist, explorer and politician.
Where To Buy
Not commercially available.
Oreomyrrhis colensoi is extremely variable throughout its range. Some botanists regard O. colensoi var. delicatula of dubious status seeing it as part of the natural variation exhibited by O. colensoi. Further study using modern taxonomic techniques and molecular markers is needed.
Fact Sheet prepared for NZPCN by P.J. de Lange (31 August 2006). Description based on Allan (1961) supplemented with observations taken from herbarium material.
References and further reading
Allan, H.H. 1961. Flora of New Zealand. Vol. I. Wellington, Government Printer.
Chung, K-F. 2007. Inclusion of the South Pacific alpine genus Oreomyrrhis (Apiaceae) in Chaerophyllum based on nuclear and chloroplast DNA sequences. Systematic Botany 32(3): 671-681.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Chaerophyllum colensoi var. delicatulum Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/chaerophyllum-colensoi-var-delicatulum/ (Date website was queried)