Species

Lepidium tenuicaule

Etymology

Lepidium: scale-shaped (pods)
tenuicaule: thin-stemmed

Common Name(s)

Shore cress

Current Conservation Status

2012 - At Risk - Declining

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

Previous Conservation Status

2009 - At Risk - Declining
2004 - Gradual Decline

Qualifiers

2012 - RR

Authority

Lepidium tenuicaule Kirk

Family

Brassicaceae

Flora Category

Vascular - Native

NVS Species Code

LEPTEN

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.

Structural Class

Dicotyledonous Herbs other than Composites

Synonyms

None

Distribution

Endemic to the North and South Islands. In the North Island probably extinct, having been recorded only from Kapiti Island. In the South Island known from Oamaru south to the islands of the Foveaux Strait.

Habitat

Coastal turf where it seems to prefer damp peaty ground free from taller shrub and grass species. Very tolerant of shade and trampling such that some large populations are known from seaside car parks, footpaths, walking tracks and around lighthouse buildings. At one time this species was even a localised urban weed at Oamaru.

Features

Rosette forming, perennial herb, arising from stout, deeply descending taproot. All parts pungent, smelling strongly of cress. Stems prostrate to ascending, glabrous (20-)80-150(-300) mm long. Leaves glabrous or glabrescent. Basal leaves persistent, pinnate, 20-100 x 0.5-0.15 mm, dark green, basally mottled with red or purple. Pinnae in (5-)7-15 pairs, acutely toothed. Stem leaves toothed at apex or entire, 5-20 x 2-5 mm, green, narrow-spathulate, linear-oblanceolate, long petiolate. Racemes 50-100 mm long at fruiting, somewhat flexuous, rachis and pedicels glabrous or sparsely hairy, pedicels distant, spreading, 2-4 mm long at fruiting. Sepals sparsely hairy, 0.5-1 x 0.3-0.5 mm. Petals 0 or if present white, < sepals. Stamens 4. silicles suborbicular, 1.5-2 x 1.5-1.8 mm, style 0.1 mm, free from narrow wing, = to or > than shallow notch, valves glabrous. Seed ovoid, brown c. 1 mm long.

Similar Taxa

Very distinctive and unlikely to be confused with any other species of lepidia. When sterile the rosette leaves have a remarkable resemblance to some species of Leptinella, from which they can be distinguished by their pungent cress smell when they are bruised.

Flowering

October - January

Flower Colours

White

Fruiting

November - February

Propagation Technique

Easy from fresh seed. With its multi-coloured ferny rosette leaves, and compact habit this is the ideal plant for places with compacted, poorly drained and otherwise bare soil, such as driveways, shaded portions of poorly drained lawns, and along the bases of brick walls.

Threats

Probably more secure than was once believed, although it does seem to have gone extinct from the North Island, Oamaru and at nearby Cape Whanbrow. Very large populations occur from about Shag Point south along the Foveaux Strait. However, some of these have been lost due to changes in habitat caused by the removal of car parks and roads that cross coastal turfs to access coastal locations. With one or two exceptions the species remains vulnerable to any change in local disturbance regimes, particularly those which encourage the growth of taller shrubs and grasses.

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

Life Cycle and Dispersal

Mucilaginous seeds are dispersed by attachment and possibly wind and water (Thorsen et al., 2009).

Where To Buy

Occasionally available from some specialist native plant nurseries.

     

References and further reading

Thorsen, M. J.; Dickinson, K. J. M.; Seddon, P. J. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285-309

This page last updated on 3 Jun 2015