Classification
 Nomenclature
Scientific Name:
Sticherus flabellatus (R.Br.) H.St.John, Occas. Pap. B. P. Bishop Mus. 17: 81 (1942)
Synonymy:
  • Gleichenia flabellata R.Br., Prodr. Fl. Nov. Holland. 161 (1810)
  • Mertensia flabellata (R.Br.) Poir., Encycl. Suppl. 3, 670 (1814)
Lectotype (designated by Perrie & Brownsey 2015): Port Jackson, [New South Wales,] R. Brown Iter. Austral. 109, BM 001038249!
  • = Gleichenia littoralis Colenso, Trans. & Proc. New Zealand Inst. 16: 344 (1884)
Lectotype (designated by Allan 1961): Great Barrier Island, C.P. Winkelmann s.n., WELT P003359!
Etymology:
From the latin flabellatus (fan-shaped), a reference to the shape of the frond.
 Description

Rhizomes long-creeping, 2.5–6 mm diameter; rhizome scales lanceate or ovate, 1.3–2.6 mm long, 0.3–0.8 mm wide, brown, ciliate, sometimes only shortly so. Fronds 180–1490 mm long. Stipes 55–1100 mm long, scaly proximally or glabrous. Laminae 90–770 mm long, 100–450 mm wide, green on both surfaces, herbaceous, scaly. Rachis buds not extending or extending once (rarely 2–3 times), scaly; not pseudostipulate. Rachis bud scales lanceate or ovate, 1.2–2.6 mm long, 0.2–0.7 mm wide, brown, ciliate. Pinnae 95–400 mm long, 120–260 mm wide; with 2–3 (rarely 1) successive pseudodichotomous forks (excluding growth from pinna buds); pinna buds not extending or rarely extending once or twice. Proximal-most (primary) costae 6–20 mm long, with 0–1 pairs of costal segments. β costae 13–75 mm long, with 3–23 pairs of costal segments. Ultimate leaflets narrowly ovate or narrowly elliptic, 100–280 mm long, 20–80 mm wide, usually at least some caudate (otherwise angustate), usually mostly straight; with 24–52 pairs of ultimate segments; pairs in centre of lamina diverging 20–40° (rarely 45°). Abaxial surface of α costae scaly; scales acicular or hair-like, 500–1600 µm long, 30–90 µm wide, pale, ciliate, glabrescent. Ultimate segments narrowly oblong or linear, 14–55 mm long, 1.5–2.5 mm wide, arising at 40–65° from α costae, crenulate, acute; abaxial surface with pale stellate scales that resemble branched hairs, glabrescent. Sori 7–18 either side of midvein, usually with 4–5 sporangia each. Spores 32–35 µm long, 17–19 µm wide (4 populations).

 Recognition

The crenulate and abaxially green ultimate segments, usually caudate leaflets, acicular or hair-like scales on the abaxial surface of the α costae, and the ultimate segments arising at ≤70° from the α costae distinguish Sticherus flabellatus from S. cunninghamii and S. tener. Sticherus flabellatus is very similar to S. urceolatus, but the former usually has longer α costae relative to the proximal-most costae, and more pronounced serrations of the ultimate segments. The difference in ploidy is reflected in the smaller spore size of S. flabellatus (32–35 µm long, 17–19 µm wide cf. 38–43 µm long, 19–23 µm wide for S. urceolatus). In New Zealand, S. flabellatus (northern North Island) and S. urceolatus (northern and western South Island) are allopatric.

 Distribution

North Island: Northland, Auckland.

Altitudinal range: 0–370 m.

Sticherus flabellatus occurs from North Cape to near Waihi in the North Island. The highest recorded altitude of c. 370 m above sea level occurs in Puketi Forest. Collections from further south are discounted because they are probably incorrectly labelled or from cultivated plants (Ōpōtiki, Baxter s.n., WELT P018468; Ōpepe, collector unknown, WELT P005416; Mt. Freeth, Picton, McMahon s.n., WELT P010704). The South Island records from near Tākaka and Stockton discussed by Given (1982) are misidentifications of other Sticherus species (Brownsey et al. 2013).

Also New Guinea, Australia (Northern Territory, Queensland, New South Wales, Victoria), New Caledonia.

 Habitat

Sticherus flabellatus frequently occurs alongside waterways, roads, and tracks, but also on bluffs, and in swamps, gumlands, and other habitats associated with high light levels. It is usually associated with scrub or low, open forest, principally Leptospermum and/or Kunzea, but it can occur in gaps within Agathis australis, podocarp, and/or broadleaved (e.g., Weinmannia, Beilschmiedia) forest.

 Biostatus
Indigenous (Non-endemic)
 Hybridisation

Sticherus flabellatus hybridises, albeit infrequently, with S. cunninghamii, based on morphological intermediacy (e.g., abaxially glaucous, but with caudate leaflets, and scales on the abaxial surface of the α costae of intermediate width): unlocalised, Colenso s.n., WELT P002888, P002890, P002891, P002897, P002905; Whangarei, A.J. Dakin s.n., AK 213848; Great Barrier Island, A.E. Wright s.n., AK 220418. The spores of WELT P002891 include a high proportion of irregular shapes, supporting the inference of hybridity. Furthermore, S. flabellatus may be a diploid progenitor, together with S. tener, of the tetraploid and putatively allopolyploid S. urceolatus (Brownsey et al. 2013).

 Cytology

n = 34 (Brownlie 1961)

 Notes

Chinnock & Bell (1998) accepted two varieties in Australia, distinguished by segment and sporangia size. The typical variety was attributed to New Zealand. The other variety, var. compactus (C.T.White & Goy) D.A.Sm., is endemic to northern Australia.

In relation to Gleichenia littoralis Colenso, the statement by Allan (1961, p.21) that "Colenso based his description on the Great Barrier specimens; the type specimen, at W [WELT]…" constitutes lectotypification because there is only one collection in WELT from Great Barrier Island (WELT P003359). It comprises three fronds. The other syntypes are: New Zealand, W. Colenso s.n., com. Dec. 1885, K! (photo WELT E471/9); Whangaruru Harbour, W. Colenso s.n., WELT P002907!

 Bibliography
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Brownlie, G. 1961: Additional chromosome numbers – New Zealand ferns. Transactions of the Royal Society of New Zealand. Botany 1: 1–4.
Brownsey, P.J.; Ewans, R.; Rance, B.; Walls, S.; Perrie, L.R. 2013: A review of the fern genus Sticherus (Gleichneiaceae) in New Zealand with confirmation of two new species records. New Zealand Journal of Botany 51(2): 104–115.
Brownsey, P.J.; Given, D.R.; Lovis, J.D. 1985: A revised classification of New Zealand pteridophytes with a synonymic checklist of species. New Zealand Journal of Botany 23(3): 431–489.
Chinnock, R.J.; Bell, G.H. 1998: Gleicheniaceae. In: Flora of Australia. Vol. 48. 148–162.
Colenso, W. 1884 ("1883"): A further contribution towards making known the botany of New Zealand. Transactions and Proceedings of the New Zealand Institute 16: 325–363.
de Lange, P.J.; Norton, D.A.; Courtney, S.P.; Heenan, P.B.; Barkla, J.W.; Cameron, E.K.; Hitchmough, R.; Townsend, A.J. 2009: Threatened and uncommon plants of New Zealand (2008 revision). New Zealand Journal of Botany 47: 61–96. [Not threatened]
de Lange, P.J.; Norton, D.A.; Heenan, P.B.; Courtney, S.P.; Molloy, B.P.J.; Ogle, C.C.; Rance, B.D. 2004: Threatened and uncommon plants of New Zealand. New Zealand Journal of Botany 42(1): 45–76.
Given, D.R. 1982: Records of Sticherus flabellatus (R.Br.) H.St John (Pteridophyta-Gleicheniaceae) from South Island, New Zealand. New Zealand Journal of Botany 20: 381–385.
Perrie, L.R.; Brownsey, P.J. 2015: Gleicheniaceae. In: Breitwieser, I; Heenan, P.B.; Wilton, A.D. (ed.) Flora of New Zealand — Ferns and Lycophytes. Fascicle 12. Manaaki Whenua Press, Lincoln.
Perrie, L.R.; Brownsey, P.J. 2015: Taxonomic notes on the New Zealand flora: lectotypes in the fern family Gleicheniaceae. New Zealand Journal of Botany 53: 183–191.
Poiret, J.L.M. 1814: Encyclopédie méthodique. Botanique. Suppl. 3. Panckoucke, Paris.
St.John, H. 1942: New combinations in the Gleicheniaceae and in Styphelia (Epacridaceae). Pacific Plant Studies 1. Occasional Papers of Bernice P. Bishop Museum of Polynesian Ethnology and Natural History 17: 79–84.