Classification
 Nomenclature
Scientific Name:
Cardamine pachyphylla Heenan, Phytotaxa 330: 118–120 (2017)
Synonymy:
Holotype: Torlesse Range, Canterbury Land District, rock outcrop, 2 March 1997, P. B. Heenan s.n., CHR 511918!
Etymology:
The specific epithet pachyphylla (Greek: thick-leaved) refers to the leaves.
 Description

Perennial herb, single rosette or with short lateral branches. Leaves up to 98 mm long, simple or occasionally pinnatifid; lamina 4.0–45.0 × 2.5–23.0 mm, grey-green, coriaceous, glabrous or occasionally with 1–3 marginal hairs; petiole up to 43 mm long. Terminal pinna 4.0–45.0 × 2.5–23.0 mm, simple, broadly elliptic to broadly elliptic-obovate, sometimes elliptic-rhomboid; margin entire to shallowly sinuate, sometimes with 2 prominent teeth, hydathodes ± indistinct; apex obtuse to subacute, with a distinct hydathode; base cuneate. Lateral pinnae 1–4, 2.0–5.0 × 1.5–3.5 mm, broadly elliptic; apex obtuse; base truncate; sessile. Cauline leaves similar to rosette leaves but smaller, narrower, base attenuate. Inflorescence racemose, with lateral racemes, terminal flowers in a cyme-like cluster, each raceme 3–22-flowered; peduncle up to 300 mm long, 0.4–1.9 mm diam. at base, ascending to erect, glabrous. Pedicels 20.0–60.0 mm long, 0.4–0.7 mm diam., glabrous. Sepals 2.9–3.0 × 1.2–1.6 mm, elliptic-oblong, saccate, green to red-brown, glabrous, margin white and membranous, apex obtuse, base truncate. Petals 4.5–5.2 × 1.9–2.5 mm, white, limb obovate; apex obtuse; base attenuate, tapering to a c. 1.0 mm long claw. Stamens 6; median filaments 4, 3.0–3.4 mm long; lateral filaments 2, 2.5–2.6 mm long; anthers 0.3–0.5 mm long, cream to pale yellow, when dehiscent held at a similar height to or slightly below the stigma. Ovary 3.2–3.4 mm long, 0.4–0.6 mm diam., ± terete, green, glabrous; ovules 56–62; style c. 0.2 mm long, ± terete; stigma 0.5–0.6 mm diam. Siliques 13.0–30.0 × 1.2–1.5 mm, glabrous, style 0.6–1.0 mm long; valves green to yellow-green at maturity and when dehiscent; replum 0.4–0.5 mm wide. Seeds 1.0–1.5 mm long, 0.65–1.0 mm wide, 0.3–0.4 mm thick, oblong, orbicular-oblong to broadly oblong, henna; wing absent.

 Recognition

Cardamine pachyphylla is distinguished from C. bilobata by its leaves having a longer and wider terminal leaflet, a smaller flower with petals 4.5–5.2 mm long, and a silique with a shorter style.

 Distribution

South Island: Marlborough, Canterbury.

Cardamine pachyphylla is known from greywacke mountains in eastern South Island, where it occurs in Torlesse Range (Canterbury) and Inland Kaikōura Range (Marlborough).

 Habitat

Cardamine pachyphylla occurs on shaded bluffs and rock outcrops, typically in lower-elevation alpine sites.

 Biostatus
Indigenous (Endemic)

Cardamine pachyphylla is assessed as having a conservation status of Threatened, Nationally Critical A(1), with the qualifier Data Poor (de Lange et al. 2018). The qualifier Data Poor is applied because this species is known with certainty from few locations and additional information is required on the number and size of the populations.

 Phenology

Flowering November–March; Fruiting November–March.

 Bibliography
de Lange, P.J.; Rolfe, J.R.; Barkla J.W.; Courtney, S.P.; Champion, P.D.; Perrie, L.R.; Beadel, S.N.; Ford, K.A.; Breitwieser, I.; Schönberger, I.; Hindmarsh-Walls, R.; Heenan, P.B.; Ladley, K. 2018: Conservation status of New Zealand indigenous vascular plants, 2017. New Zealand Threat Classification Series. No. 22. [Nationally Critical]
Heenan, P.B. 2017: A taxonomic revision of Cardamine L. (Brassicaceae) in New Zealand. Phytotaxa 330(1): 001–154.
Heenan, P.B. 2020: Cardamine. In: Wilton, A.D. (ed.) Flora of New Zealand - Seed Plants. Fascicle 6. Manaaki Whenua Press, Lincoln.