Species

Hypolepis dicksonioides

Etymology

Hypolepis: From the greek hypo (under) and lepis (scale), referring to the position of the sori on the ferns

Common Name(s)

Giant hypolepis, ground fern (Norfolk Island only)

Current Conservation Status

2012 - At Risk - Naturally Uncommon

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 - Naturally Uncommon
2004 - Sparse

Qualifiers

2012 - EF, SO, Sp
2009 - SO, EF

Authority

Hypolepis dicksonioides (Endl.) Hook.

Family

Dennstaedtiaceae

Flora Category

Vascular - Native

NVS Species Code

HYPDIC

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

Ferns

Synonyms

Hypolepis tenuifolia sensu Hook.f.; Hypolepis tenuifolia var. pellucida (Colenso) Hook.; Cheilanthes dicksonioides Endl.; Cheilanthes pellucida Colenso; Hypolepis endlicheriana C.Presl

Distribution

Indigenous. Kermadec Islands (Raoul, Macauley Islands). New Zealand: Three Kings, North, South and Rekohu (Chatham Island). Known in the North Island from Te Paki south to Wellington but mainly coastal and absent from large parts of the island (it has also been recorded as a 'weed' in Auckland, Hamilton, Tauranga and Wellington). Locally common around Geothermal areas of the Taupo Volcanic Zone. In the South Island known only from the coast north-west Nelson and northern Westland. Present on Norfolk, Samoa, Tahiti. Cook and the Marquesas islands.

Habitat

A weedy speces of coastal, lowland and geothermal habitats. Naturally short-lived, plants may appear as and when suitable habitat is generated following disturbance. As such this species has also appeared in urban situations and can from time to time be found growing in cities on rock walls, in bark gardens, or even protruding from cracks in asphalt pavements. It has also been recorded as a weed in garden centres.

Features

Rhizome long-creeping, (3–)4–8 mm diam., densely covered in pale brown hairs near growing apex, more scattered and becoming red-brown elsewhere, giving rise to stipes at intervals of 1.0–2.8 m. Stipes (0.15–)0.2–1.0 m long, (2–)5–15 mm diam., red-brown at base, becoming pale red-brown or yellow-brown above, bearing red-brown hairs at very base, soon replaced by colourless glandular and eglandular hairs (up to 5 mm long on uncoiling fronds); two dark, prominent, vertical bands on opposite sides of stipe. Laminae broadly ovate or elliptic (0.02–)0.035–1.35 × (0.015–)0.035–1.1 m, bipinnate at apex, 4 or 5-pinnate at base. Rachis yellow-brown at base, green at apex, bearing colourless glandular and eglandular hairs (up to 3 mm long). Primary pinnae in 15–30 pairs, opposite or subopposite, lower pair arising at 3–50° to stem; longest pair below middle, usually basal, (110–)200–700 × (70–)140–450 mm; lowest ones (50–)100–400 mm apart, middle ones 2–5 mm apart; upper ones narrowly ovate, lower ones ovate. Secondary pinnae ovate, (45–)70–300 × 30–150 mm, those on the lower pinnae decreasing markedly in length along the pinnae. Tertiary pinnae ovate, (16–)20–80 × (7–)10–35 mm, midrib winged. Quaternary pinnae narrowly ovate, 7–16 × 2–6 mm, shallowly incised on smaller specimens, divided into 4–5 pairs of ultimate segments on larger specimens. Veins reaching margin at a tooth apex, or sometimes ending just short of margin. Hairs: colourless glandular and eglandular hairs on midribs and veins of both lamina j surfaces but absent from margins, 0.3–1.5 mm long. Sori on upper margin of each ultimate segment, situated at vein endings, protected by obvious reflexed flaps (green at base, membranous at apex, incised); protected from earliest stages. Spores pale brown, echinate.

Similar Taxa

Could only be confused with H. ambigua from which it can be immediately recognised by its very much larger, more finely divided, extremely glandular sticky, deltoid fronds, thicker stipes, and conspicuous reflexed membranous indusia. The fronds are often so sticky that insects, dirt, feathers and hair is trapped on them.

Flowering

Not applicable - spore producing

Flower Colours

No Flowers

Fruiting

Not applicable - spore producing

Propagation Technique

Easily grown from fresh spores. Inclined to become invasive and weedy in garden situations. Despite this the extremely robust, strongly deltoid, bright green fronds are rather attractive. It is naturally rather short-lived but rapidly establishes by spores in ideal situations. It is frost tender although established plants merely die back during winter.

Threats

Hypolepis dicksonioides is a short-lived, naturally ephemeral, opportunistic species, which requires frequnet disturbance to create fresh habitats to colonise. As such it is naturally uncommon, and biologically sparse. In the main islands of New Zealand it is usually scarce. However, on the Kermadec Islands, especially Macauley Island it forms the dominant vegetation.

Chromosome No.

2n = 208

Endemic Taxon

No

Endemic Genus

No

Endemic Family

No

Life Cycle and Dispersal

Minute spores are wind dispersed (Thorsen et al., 2009).

Attribution

Fact sheet prepared for NZPCN by P.J. de Lange (1 February 2005). Description from Brownsey & Chinnock (1984).

References and further reading

Brownsey, P.J.; Chinnock, R.J. 1984: A Taxonomic revision of the New Zealand species of Hypolepis. New Zealand Journal of Botany 22: 43-80.

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 30 May 2015