The New Zealand Plant Conservation Network

Species

Gleichenia inclusisora

Etymology

Gleichenia: After the German naturalist and plant physiologist Wilhelm Friedrich (Baron) von Gleichen (1717-1783)
inclusisora: Inclusus - Latin, meaning enclosed, and here referring to the sori of G. inclusisora being embedded within the lamina

Common Name(s)

tangle fern

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

Qualifiers

2012 - DP, RR
2009 - RR

Authority

Gleichenia inclusisora Perrie, L.D.Sheph., et Brownsey

Family

Gleicheniaceae

Brief Description

Tangle fern. Rhizomatous. Fronds umbrella-like, upper surface green, glossy, undersides white (or blue-green). Sori, in clusters of three or four, these embedded up to 3/4 of their depth in a small pit in the lower frond surface.

Flora Category

Vascular - Native

Structural Class

Ferns

Synonyms

None (first described in 2012)

Distribution

Endemic. New Zealand: North and South Islands from Te Moehau to Westland but often absent from large parts of this range

Habitat

Lowland to montane (850 m on Te Moehau). Inhabiting pakihi (wet, infertile heaths) and open shrubland/treeland. Gleichenia inclusisora has been recorded growing with G. alpina and G. microphylla, but it is most commonly associated with G. dicarpa.

Features

Terrestrial fern. Rhizomes long-creeping, 1-3mm diameter, brown, with stipes arising at intervals of 5-90mm (or more), scaly. Rhizome scales sparse to numerous, 0.5-1.2 × 0.5-0.8mm, ovate to orbicular, dark brown to nearly black, margins entire or nearly so, peltate, bullate. Stipes 40-1100 mm long, 1.0-2.5mm diameter, widest distally, proximally dark brown, distally straw-green when young or brown when old, glabrous except for occasional, proximal scales that are like those of the rhizome. Rachis buds 2.0-3.1 × 1.2-2.1 mm, often not producing a rachis so that fronds form a single tier of pinnae, but sometimes 2-4 tiers, with rachis inter-tier lengths of 15-280 mm. Rachis bud scales 1.5-2.5 × 1.0-1.5 mm, ovate, marginate, dark brown with a pale brown or clear margin, ciliate to erose, peltate. Pinnae 50->950 × 50-300 mm, with 0-6 pseudodichotomous branchings. Pinna buds similar to rachis buds but generally smaller. Distal costae (nerves) appearing tetragonal or nearly so on the adaxial surface, with lateral ridges. Proximal costae glabrescent, straw-green when young, brown when old. Gamma costae 10-40mm long, with 0-4 pairs of ultimate leaflets; indument similar to beta costae but sparser. Beta costae 25-135mm long, with 5-26 pairs of ultimate leaflets and a terminal ultimate leaflet 10-44mm long; adaxially with long-ciliate, reduced scales that are abundant and orange-brown when young or sparse and white when old; abaxially with a mixture of scales like those on the pinna buds and ultimate segments, glabrescent. Longest ultimate leaflets 18-59mm long, with 15-47 pairs of ultimate segments. Alpha costae adaxially glabrous (or with occasional reduced scales like those of the beta costae when young), abaxially with scales like those of the ultimate segments. Ultimate segments 0.7-1.4 × 0.9-1.4 mm, adaxially green and glabrous, abaxially white (sometimes glaucous) and abundantly (when young) to sparsely scaly, abaxial surface flat to recurved 90 degrees but lateral margins at most only slightly raised (not pouched), apices rounded and revolute. Scales on abaxial surface of ultimate segments 0.3-0.8 × 0.3-0.6 mm, orbicular to ovate, with dark brown centre and pale brown margins, long-ciliate, peltate, bullate; similar but larger (to 1.0mm long), ovate scales covering young ultimate leaflets. Sori 0.4-0.5mm diameter, each comprising three pale yellow sporangia embedded to c.3/4 of their depth in a pit within the abaxial surface of the lamina; one sorus per ultimate segment, in the proximal acroscopic corner. Spores trilete, yellow.

Similar Taxa

Gleichenia inclusisora is distinguished from the other three New Zealand species of Gleichenia (G. alpina, G. dicarpa and G. microphylla) by the sori which are embedded rather than flush or proud from the lamina; by the bicolorous, orbicular to ovate, peltate scales on the abaxial surfaces of the ultimate segments; by the glabrous stipes; glabrous proximal costae (nerves); by the ultimate segments which are unpouched and abaxially white; and by pinnae that divide pseudodichotomously several times. Of the other three New Zealand species it most often grows with G. dicarpa from which G. inclusisora can be visually recognised in the field by the shinier upper frond surface which contrasts strongly with the usually duller G. dicarpa upper frond surface.

Flowering

Not applicable - spore producing

Fruiting

Not applicable - spore producing

Propagation Technique

Unknown. Probably best left alone.

Threats

Gleichenia inclusisora is known from at least 17 sites collectively occupying an area of >300 square kilometres. As Gleichenia inclusisora was a chance discovery (Perrie et al. 2012) the naming authors note that it is likely to be found elsewhere in New Zealand (especially now that it has been formally described). Perrie et al. (2012) using the New Zealand Threat Classification System (Townsend et al. 2007) recommend a conservation status of "At Risk / Naturaly Uncommon" - qualified "RR" [Range Restricted]. This assessment has been accepted by the New Zealand Indigenous Vascular Plant Threat Listing Panel (de Lange et al. 2013).

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 20 Oct 2014