Classification
 Nomenclature
Scientific Name:
Asplenium cimmeriorum Brownsey & de Lange, New Zealand J. Bot. 35: 283 (1997)
Synonymy:
Holotype: South Island, Westland, near Punakāiki, P.J. Brownsey, 3 Mar. 1992, WELT P017320!
Etymology:
From the Latin Cimmeriorum (of the Cimmerii, a mythical people said by Homer to inhabit a remote region of mist and darkness, which has given rise to the proverbial expression “Cimmerian darkness”), a reference to the habitat of this species.
 Description

Terrestrial or rupestral ferns. Rhizomes short-creeping, up to 70 mm long (in herbarium specimens), 3–5 mm diameter, bearing scales. Rhizome scales narrowly ovate or ovate, 4–10 mm long, 0.5–2 mm wide, blackish-brown, clathrate. Fronds 45–370 mm long. Stipes 20–150 mm long, yellow-brown or green, bearing ovate scales with short filiform projections throughout. Rachises green, scaly. Laminae 1-pinnate-pinnatifid to deeply 2-pinnate-pinnatifid, narrowly triangular or narrowly ovate or ovate, tapering gradually to the apex, 25–220 mm long, 10–78 mm wide, mid- to dark green on both surfaces, herbaceous, bearing scattered scales, lacking hairs. Primary pinnae in 3–18 pairs below pinnatifid apex, not or only slightly overlapping; proximal pinnae ovate, those at mid-lamina ovate or narrowly ovate; the longest below the middle, 7–55 mm long, 3–17 mm wide, apices obtuse, bases stalked. Secondary pinnae gradually decreasing in length along each primary pinna to the distal end, the basal acroscopic one the largest; the longest proximal secondary pinnae elliptic or ovate, 5–13 mm long, 1–7 mm wide, apices obtuse, incised or partly divided into tertiary segments, bases short-stalked or sessile; the distal secondary pinnae oblong, apices obtuse, bases adnate. Sori away from margin; indusia 1.5–3.5 mm long, straight; free margins of indusia entire or irregularly incised. Mean spore size 44–52 μm long, 33–39 μm wide; perispores with anastomosing wings and low tuberculae in the lacunae.

 Recognition

Asplenium cimmeriorum is morphologically similar to A. bulbiferum, A. gracillimum, and A. hookerianum, but differs from all three in having a short-creeping rhizome. It has generally smaller fronds than either A. bulbiferum or A. gracillimum, and lacks the bulbils of those species. It has a slightly narrower frond than A. hookerianum, and is octoploid rather than tetraploid, with larger spores (44–52 × 33–39 μm cf. 31–37 × 23–27 μm). Its habitat is also distinctive.

 Distribution

North Island: Auckland, Taranaki.

South Island: Western Nelson.

Altitudinal range: 5–620 m.

In the North Island Asplenium cimmeriorum occurs only in the Waitomo area of western Waikato, where it grows from 160 m to 460 m. In the South Island it occurs in north-west Nelson and north Westland from Gouland Downs to Punakāiki, growing from near sea level up to 620 m on the Heaphy Track. There are also occasional records from the Inangahua and Buller Valleys.

 Habitat

Asplenium cimmeriorum is largely confined to dark, calcareous sites in high-rainfall, lowland to montane areas (Brownsey & de Lange 1997). It grows most frequently at limestone cave entrances, under overhangs, on cave walls and ceilings or associated rockfalls, or sometimes in deeper caves near the limit of daylight penetration. In the South Island, plants also extend out into surrounding forest, growing on rotting logs, amongst tree roots, or on limestone boulders and rock faces.

 Biostatus
Indigenous (Endemic)

Asplenium cimmeriorum was given a conservation status of Naturally Uncommon by de Lange et al. (2013).

 Hybridisation

There is evidence that A. cimmeriorum hybridises with A. bulbiferum (Brownsey & de Lange 1997).

 Cytology

n = c. 144 (Brownsey & de Lange 1997).

 Notes

DNA analyses strongly suggest that A. cimmeriorum is an allopolyploid species derived from A. bulbiferum and A. hookerianum, and that the populations from the North and South Island have independent polyploid origins (Shepherd et al. 2008; Perrie et al. 2010).

 Bibliography
Brownsey, P.J.; de Lange, P.J. 1997: Asplenium cimmeriorum, a new fern species from New Zealand. New Zealand Journal of Botany 35(3): 283–292.
Brownsey, P.J.; Perrie, L.R. 2018: Aspleniaceae. In: Breitwieser, I.; Wilton, A.D. (ed.) Flora of New Zealand — Ferns and Lycophytes. Fascicle 18. Manaaki Whenua Press, Lincoln.
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. [Naturally uncommon]
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.
de Lange, P.J.; Rolfe, J.R.; Barkla J.W.; Courtney, S.P.; Champion, P.D.; Perrie, L.R.; Beadel, S.N.; Ford, K.A.; Breitwieser, I.; Schönberger, I.; Hindmarsh-Walls, R.; Heenan, P.B.; Ladley, K. 2018: Conservation status of New Zealand indigenous vascular plants, 2017. New Zealand Threat Classification Series No. 22. [Naturally Uncommon]
de Lange, P.J.; Rolfe, J.R.; Champion, P.D.; Courtney, S.P.; Heenan, P.B.; Barkla, J.W.; Cameron, E.K.; Norton, D.A.; Hitchmough, R.A. 2013: Conservation status of New Zealand indigenous vascular plants, 2012. New Zealand Threat Classification Series 3. Department of Conservation, Wellington. [Naturally Uncommon]
Perrie, L.R.; Shepherd, L.D.; de Lange, P.J.; Brownsey, P.J. 2010: Parallel polyploid speciation: distinct sympatric gene-pools of recurrently derived allo-octoploid Asplenium ferns. Molecular Ecology 19: 2916–2932.
Shepherd, L.D.; Perrie, L.R.; Brownsey, P.J. 2008: Low-copy nuclear DNA sequences reveal a predominance of allopolyploids in a New Zealand Asplenium fern complex. Molecular Phylogenetics and Evolution 49: 240–248.