Sticherus flabellatus var. flabellatus
Common name
Umbrella fern
Synonyms
Gleichenia flabellata R. Br.
Family
Gleicheniaceae
Flora category
Vascular – Native
Endemic taxon
No
Endemic genus
No
Endemic family
No
Structural class
Ferns
Chromosome number
2n = 68
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley.
2012 | Not Threatened
Previous conservation statuses
2009 | Not Threatened | Qualifiers: SO
2004 | Sparse
Distribution
Indigenous. In New Zealand known from scattered locations from North Cape south to the Karangahake Gorge. Probably most common on Great Barrier Island.
There has been some confusion over the distribution of Sticherus flabellatus in New Zealand. Perrie (2013) stated: “Populations of Sticherus tener and Sticherus urceolatus in the northern South Island had previously been mistakenly attributed to Sticherus flabellatus. We now believe that Sticherus flabellatus does not occur in the South Island, but it is common in the northern North Island.”
Common in Australia.
Habitat
Coastal to lowland. In the North Island usually associated with kauri (Agathis australis) forest, and/or regenerating forest and scrub nearby established kauri forest remnants. It also grows along steep sided streams and on rocks within gorges.
Features
Colonial yellow-green to green umbrella fern. Fronds erect 1–1.4 m tall, rather glossy above, dull below. Stipes 0.2–0.6 m long, pale brown, glabrous, rather wiry. Rachises in 1(–2) tiers, each forking 2–3 times, 100–300 mm from the stipe to the tip of the longest branch, erect and spreading, flabellate, glabrous or slightly scaly. Pinnae linear up to 40 x 3 mm, apex acute, glossy yellow-green to green above paler beneath. Sori in one row either side of the midrib but away for the pinna margins, 4–5 sporangia in each, without indusia. Description adapted from Chinnock & Bell (1998).
According to Brownsey et al. (2013), “Sticherus flabellatus has fronds that are held partially upright in the form of a fan, rather than drooping like an umbrella. There is a very narrow angle (mean 30°) between paired proximal costae. The ultimate leaflet is much longer than the proximal costa (mean ratio 15.5 : 1). The proximal costa usually lacks leafy ultimate segments. The ultimate leaflet is narrowly elliptic in outline with the segments arising at 50-60° to the costa. The segments of the ultimate leaflet are longest near the middle, 20-40 mm long, 1.5-2 mm wide, minutely serrate along the margins, and green on the underside. There are occasional, very narrow, fimbriate, brown scales along the costae, and hair-like scales on the undersurfaces. Spores measure 32-35 mm by 17-19 mm (four samples from four populations).”
Similar taxa
Rather distinctive, the broad, fan-shaped, yellow-green to green concolorous fronds serve to distinguish it from the only other common Sticherus in New Zealand, S. cunninghamii (Hook.f.) Ching, which has much more divided fronds, with shorter pinnules dark green above and whitish beneath. Its pinnae are also markedly more scaly. Distinction from the little known (in New Zealand) S. tener (R.Br.) Ching is less clear, but this species has its pinnae arising at right angles to the rachis branches.
Flowering
Not applicable - spore producing
Flower colours
No flowers
Fruiting
Not applicable - spore producing
Propagation technique
Can be grown from rooted pieces and fresh spores. However, spores can be very tricky to raise and plants resent root disturbance. Nevertheless, once established this species is one of the few members of the New Zealand Gleicheniaceae that is easily maintained in cultivation.
Threats
Not actively threatened. However, with the exception of Great Barrier Island it is never common anywhere, and some populations are very small and vulnerable to land clearance and mining.
Etymology
sticherus: In rows; from the greek sticheres; arrangement of the spore clusters
flabellatus: Fan shaped; from the Latin flabellum; shape of the leaves
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange (January 2005). Description adapted from Chinnock & Bell (1998). Updated by Melissa Hutchison (19 November 2022), with reference to Brownsey et al. (2013).
References and further reading
Brownsey P.J., Ewans R., Rance B., Walls S. and Perrie L.R. 2013: A review of the fern genus Sticherus (Gleicheniaceae) in New Zealand with confirmation of two new species records. New Zealand Journal of Botany 51(2): 104-115. https://doi.org/10.1080/0028825X.2013.773917DOI: 10.1080/0028825X.2013.773917
Chinnock, R.J.; Bell, G.H. 1998: Gleicheniaceae. Flora of Australia 48: 148-162.
Perrie L. 2013: Would you mine a rare population? Blog on the Museum of New Zealand/Te Papa Tongarewa website. https://blog.tepapa.govt.nz/2013/04/21/would-you-mine-a-rare-population/