Pachycladon exile
Synonyms
Ischnocarpus exilis Heenan, Pachycladon exilis (Heenan) Heenan et A.D.Mitch. orth.var.
Family
Brassicaceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Herbs - Dicotyledons other than Composites
Chromosome number
2n = 20
Current conservation status
The conservation 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.
Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – an interim threat classification status has not been assessed by the NZTCS panel.
- Conservation status of New Zealand indigenous vascular plants, 2017 . 2018. 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. Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | Threatened – Nationally Critical | Qualifiers: CD, OL
Previous conservation statuses
2012 | Threatened – Nationally Critical | Qualifiers: CD, OL
2009 | Threatened – Nationally Critical | Qualifiers: CD, OL
2004 | Threatened – Nationally Critical
Distribution
Endemic. New Zealand: South Island (South Canterbury and North Otago. Formerly present in a number of sites along the Waitaki River and at Cape Wanbrow. Now apparently confined to a single site near Awahokomo Creek).
Habitat
A species apparently favouring dry, exposed limestone rock and associated rendzina soils. It seems to require open ground to thrive and is intolerant of much competition with other plants.
Detailed description
Slender, grey-green, thread-like perennial herb, up to100 mm tall. Basal leaves 7–20 mm long, simple, initially densely invested with stellate hairs, becoming glabrescent with age; early basal leaves elliptic, entire or with a few blunt serrations, later leaves pinnatifid to pinnatisect, lobed 2–4 times in opposite to subopposite pairs; lamina, 4–9 × 1.5–5 mm. Stem leaves 1–4, lower ones similar to basal leaves, upper 3 × 0.5 mm, linear, minutely serrated. Inflorescences racemose, 40–100 mm long, glaucescent, 3–10-flowered. Pedicels 8–12 × 0.4–0.5 mm, glabrous. Sepals 1.8–2.4 × 1–1.1 mm, green with pale margins, ascending, oblong to elliptic, subacute. Petals 3–5 × 0.3–1 mm, white, obovate to obovate-spathulate, subacute. Stamens 4–6, anthers green to green-brown. Style 0.1–0.2 mm, green. Siliques 15–25 × 0.7–1 mm, green to brown-green, terete, usually curved, glabrous. Seeds 0.6–0.9 mm, pale brown, short-oblong.
Similar taxa
Similar to Pachycladon cheesemanii Heenan et A.D.Mitch. but smaller in all parts and with an ovary circular (terete) in cross-section.
Flowering
October–November
Flower colours
Green, White
Fruiting
October–December
Propagation technique
Easily grown from fresh seed. A short-lived, fairly non-descript plant which does best in a sunny exposed situation, growing within a fertile, free draining, soil. This is more of a plant for a specialist as it is not particularly attractive, and very prone to fungal diseases and insect damage. The foliage is edible.
Threats
Threatened by the very small number (< 50 individuals) of plants known from the wild. These plants are confined to a single limestone outcrop where they are at risk from the spread of weeds such as Festuca rubra, hawkweed (Pilosella spp.) and cocksfoot (Dactylis glomerata), and erosion caused by excessive rabbit browsing pressure on the associated rock outcrop vegetation.
Etymology
exile: From the Latin exile (thin, slender, feeble, meager)
Where To Buy
Not commericially available.
Attribution
Fact Sheet prepared for NZPCN by P.J. de Lange 1 July 2007. Description by P.B. Heenan and published in de Lange et al. (2010) - see also Molloy et al. (1999)
References and further reading
de Lange PJ, Heenan PB, Norton DA, Rolfe JR, Sawyer JWD. 2010. Threatened Plants of New Zealand. Canterbury University Press, Christchurch. 471 p.
Molloy BPJ, Edgar E, Heenan PB, de Lange PJ. 1999. New species of Poa (Gramineae) and Ischnocarpus (Brassicaceae) from limestone, North Otago, South Island, New Zealand. New Zealand Journal of Botany 37(1): 41–50. https://doi.org/10.1080/0028825X.1999.9512610.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Pachycladon exile Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/pachycladon-exile/ (Date website was queried)