Pachycladon stellatum
Common names
Starry cress
Synonyms
Cheesemania fastigiata var. stellata Allan, Cheesemania stellata (Allan) Heenan et Garn.-Jones; Pachycladon stellata (Allan) Heenan et A. 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
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.
PACSTE
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: DP
Previous conservation statuses
2012 | Threatened – Nationally Critical | Qualifiers: DP
2009 | Threatened – Nationally Critical | Qualifiers: DP
2004 | Serious Decline
Distribution
Endemic to the upper reaches of several river systems of inland South Marlborough and the Kaikoura Ranges and Upper Awatere.
Habitat
Upland to subalpine rocks, on ledges, crevices, cracks and overhanging bluffs. Often found on shaded, south-facing sites.
Detailed description
Polycarpic perennial rosette-forming herb, up to 340 mm tall; rootstock stout, up to 16 mm diameter. Rosette, densely leafy, foliage coriaceous, dull, grey-green, often red-purple on petiole and lower surface. Leaves 20–80 × 5–19 mm, narrow-lanceolate, lanceolate, or oblanceolate, shallowly serrate with 4–8 pairs of teeth; apex acute to subacute; base attenuate. Hairs on leaves and inflorescence bifurcating, dendritic, sometimes simple, white or sordid, harsh or scabrid. Inflorescence 150-350 mm, compound, with terminal and lateral racemes, lateral racemes alternate and occasionally with secondary racemes. Cauline leaves subtending lateral racemes and rarely lowermost flowers, 3.5–55 × 1–5 mm, similar to rosette leaves, becoming smaller and linear up stem, moderately to densely hairy; base cuneate to subauriculate . Racemes 60-200 mm long at fruiting, 10-40-flowered; sparsely to densely covered in hairs. Pedicels 4.0-5.5 mm long at flowering, 7–15 mm long at fruiting, usually glabrous, suberect to erecto-patent. Sepals 3.5–4.5 × 1.3–2.1 mm, ascending, green, oblong, with few hairs, often flushed pink in bud; margin broad, membranous, white; apex obtuse to subacute. Petals 6–7 × 3–4 mm, white; claw 2.0–3.5 mm long; limb broad elliptic to obovate, or short oblanceolate, 3.0–3.5 mm long; apex rounded; base attenuate to cuneate . Stamen filaments 2.5–4.9 mm long; anthers 0.9–1.1 × 0.5–0.6 mm, white. Nectary almost surrounding the bases of the lateral stamens. Ovary 2.6–4.1 × 0.5–0.8 mm, green, glabrous. Style 0.3–0.7 mm long . Stigma 0.4–0.5 mm wide. Siliques 30–60 × 1.3–2.3 mm, linear, valves weakly keeled at base, 1-veined, at maturity yellow-brown and often flushed red-brown . Septum intact, with or without a midvein. Funicle 0.3–0.5 mm long. Seeds 30–50 per locule, 1.1–1.4 × 0.5–0.7 × 0.3–0.4 mm, oblong to narrowly ellipsoid, flattened, brown or red-brown; surface regular to irregular, reticulate; wing usually apical but sometimes decurrent on apical half of seed, 0.2–1.0 mm long at seed apex.
Similar taxa
Pachycladon stellatum could be confused with P. enysii and P. fastigiata. Pachycladon stellatum has grey-green leaves with shallow regular lobes, dense star-shaped hairs and long flowering stems. P. fastigiata has sharply-toothed leaves. P. enysii has short flower stems. In general, readily distinguished from other rossette-forming Pachycladon by the narrow lanceolate to oblanceolate, serrate, grey-green leaves which are densely covered in small bifurcating and dendritic hairs.
Flowering
November to January
Flower colours
Green, White
Fruiting
January to April
Propagation technique
Difficult. Should not be removed from the wild.
Threats
A rather localised species, which is unusual for the genus in that it extends from montane to lowland cliff and rock outcrop habitats. In these sites plants are vulnerable from weed competition, browsing animals such as goats, and plant collectors. At least one population has gone extinct through the actions of plant collectors. Most of the known sites are small and mature reproductive individuals are scarce. Indications are that many of the known populations are declining rapidly, though the exact cause(s) is/are unknown.
Etymology
stellatum: With spreading, star-like rays
Where To Buy
Not generally available commercially but plants are held by specialist growers.
Attribution
Description based on Heenan et al. (1999).
References and further reading
Heenan, P.B; Garnock-Jones, P.J. 1999: A new species combination in Cheesemania (Brassicaceae) from New Zealand. New Zealand Journal of Botany 37: 235–241