The New Zealand Plant Conservation Network

Species

Cardamine magnifica

Etymology

Cardamine: From the Greek name kárdamon, referring to an Indian spice
magnifica: Meaning 'splendid'

Common Name(s)

Castlehill bittercress

Current Conservation Status

2019 - Threatened - Nationally Critical

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Authority

Cardamine magnifica Heenan

Family

Brassicaceae

Brief Description

Allied to Cardamine glara from which it differs by its more robust growth habit, strongly rhizomatous stems, larger and thicker leaves, conspicuous and larger flowers, larger sepals and petals, longer anthers, filaments and styles, and longer seeds with a winged margin.

Flora Category

Vascular - Native

Structural Class

Dicotyledonous Herbs other than Composites

Synonyms

None - first described in 2019

Distribution

Endemic. South Island, Canterbury, Castle Hill Basin (including Castle Hill, Gorge Hill, and Prebble Hill),

Habitat

A plant inhabiting fine-grained limestone scree, stony colluvium, and also growing on t the margins of associated sparsely vegetated, stable to semi-stable limestone rock outcrops and bluffs.

Features

Perennial herb, single rosette or with short lateral branches, stem and branches 1.0–1.5 mm diameter, strongly rhizomatous. Leaves up to 80 mm long, pinnatisect; lamina 10.2–55.0 × 12.0–28.0 mm, grey-green, light green, greenish-yellow, sometimes purplish beneath, coriaceous, usually glabrous, occasionally with sparsely hairy margins and petiole. Terminal pinna 4.0–16.0 × 4.0–17.0 mm, usually simple, sometimes with 1–2 very shallow lobes, orbicular, orbicular-rhomboid, to broadly elliptic-rhomboid, margin often irregular, apex obtuse with a conspicuous hydathode, base obtuse, truncate or weakly cordate and sometimes oblique. Lateral pinnae 2–4, 2.0–11.0 × 2.0–10.0 mm, orbicular, orbicular-rhomboid, to broadly elliptic-rhomboid, petiolule 0.5–8.0 mm long. Petiole up to 65 mm long; hairs septate and 0.3–0.4 mm long. Cauline leaves similar to rosette leaves but smaller and with fewer lateral pinnae. Inflorescence racemose, 7–15-flowered; peduncle up to 140 mm long, 0.8–1.4 mm diam. at base, upright, glabrous. Pedicels 12.0–37.0 mm long, 0.4–0.5 mm diam., glabrous. Sepals 2.6–4.5 × 1.5–2.2 mm, elliptic-oblong to broadly elliptic, ± saccate, green or red-brown, usually glabrous or occasionally sparsely hairy in distal half, margin translucent or white, membranous, apex obtuse, base truncate. Petals 7.6–11.3 × 3.8–5.0 mm, white, limb obovate to broadly elliptic; apex obtuse; base cuneate, tapering to a 1.0–1.4 mm long claw. Stamens 6; median filaments 4, 3.6–4.0 mm long; lateral filaments 2, 3.2–3.4 mm long; anthers 0.8–0.9 mm long, cream to pale yellow, when dehiscent held at a similar height to or slightly below the stigma. Ovary 3.5–4.2 mm long, 0.5–0.6 mm diam., ± terete, green, glabrous; ovules 18–22; style 2.0–4.0 mm long, ± terete; stigma 0.7–0.8 mm diam. Siliques 33.0–40.0 × 1.5–1.8 mm, glabrous, style 1.8–3.0 mm long; valves green to red-brown at maturity; straw-coloured when dehiscent, replum 0.3–0.4 mm wide. Seeds 1.4–1.9 mm long, 0.7–1.1 mm wide, 0.3–0.5 mm thick, broad-oblong, oblong to oblong-elliptic, yellowbrown to henna; wing present.

Similar Taxa

At Castle Hill Basin, Cardamine magnifica occurs with C. coronata, C. glara and C. intonsa. In comparison to C. glara, C. magnifica has a more robust growth habit, strongly rhizomatous stems, thicker, more robust and larger leaves, conspicuous and larger flowers, larger sepals and petals, longer anthers, filaments and styles, and longer seeds with a winged margin. Cardamine coronata is readily distinguished by its leaflet axillary hydathodes and the hairy silique, C. intonsa has hairy leaves and siliques, and both species have smaller sepals, petals, anthers, filaments, and seeds.

Flowering

October - December

Flower Colours

White,Yellow

Fruiting

December - March

Propagation Technique

Not known from cultivation.

Threats

Heenan & Molloy (2019) recommend that Cardamine magnifica be assessed as 'Threatened, Nationally Critical' (Criterion “A” of very small population (natural or unnatural), however they also note that following criteria for 'Nationally Critical' also apply: A(1) < 250 mature individuals and A(3) total area of occupancy ≤ 1 hectare see Townsend et al. (2008). Heenan & Molloy (2019) also advise that the species be qualified 'DP' (data poor) due to the lack of population size and trend data (see Townsend et al. 2008).

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 5 Sep 2019