Classification
 Nomenclature
Scientific Name:
Thelypteridaceae Pic.Serm., Webbia 24: 709 (1970)
 Description
Terrestrial (NZ) or rarely epiphytic (not NZ) ferns. Rhizomes short- to long-creeping, erect or forming a short arborescent trunk, scaly. Fronds monomorphic or rarely dimorphic, not articulated to rhizome. Laminae undivided (not NZ) or 1-pinnate to 3-pinnate-pinnatifid (NZ), catadromous, herbaceous or coriaceous, usually hairy, sometimes bearing glands, rarely also scaly, often with aerophores in two lines on stipe and rachis and on abaxial surfaces at bases of pinnae. Veins free (NZ), or with one or more basal veins from adjacent pinna lobes uniting below the sinus (NZ), or rarely reticulate (not NZ). Sori round (NZ) or slightly elongate (not NZ), superficial, borne on abaxial surface away from margins; paraphyses usually absent or rarely present; indusia reniform, irregularly shaped or absent; sporangial maturation mixed. Sporangia with vertical annulus, usually 64 spores per sporangium. Homosporous; spores monolete (NZ) or rarely trilete (not NZ), lacking chlorophyll; perispores reticulate, winged, echinate or tuberculate.
 Taxonomy
A family of 5–25 genera depending on authority, and almost 1000 species.

Taxonomic classification of the family remains uncertain with many different treatments having been proposed. At one extreme, Christenhusz & Chase (2014) suggest that the Thelypteridaceae should be subsumed within a greatly expanded Aspleniaceae. However, that would create a very large family that is difficult to define morphologically, and the concept is not accepted here. Most recent authorities, including Smith et al. (2006), recognise Thelypteridaceae as a clearly defined, monophyletic family, but subdivision of the family is more contentious. Smith et al. (2006) recognise only Cyclosorus, Macrothelypteris, Phegopteris, Pseudophegopteris and Thelypteris, which Christenhusz & Chase (2014) would reduce further to just three genera, whereas Holttum (1971, 1977, 1982) grouped the Old World species into 25 genera. Holttum’s treatment has been criticised for needing combinations of characters to define genera, and because generic boundaries are blurred by possible hybridisation and transitional species (Smith 1990). Smith (1971) and Smith et al. (2006) included Christella within a more broadly circumscribed Cyclosorus. Molecular evidence is still preliminary and not yet conclusive, especially with respect to the clade that includes Christella, Cyclosorus and Pneumatopteris (Smith & Cranfill 2002; He & Zhang 2012). The most recent work suggests that Christella is polyphyletic, with most Paleotropical species, including C. dentata, not congeneric with Neotropical species (Almeida et al. 2016). Until there is greater clarity in the circumscription of these genera, we follow Holttum’s long-standing treatment of the family in the Pacific and Australasia (Holttum 1977) to provide consistency and comparability with listings for Australia (Bostock 1998), Fiji (Brownsey & Perrie 2011) and the south-west Pacific (Nakamura 2008).

On the basis of Holttum’s classification, the family is represented in New Zealand by five indigenous genera – Christella, Cyclosorus, Macrothelypteris, Pneumatopteris and Thelypteris. In stark contrast to the diversity in Australia and the Pacific, each of these genera is monotypic in New Zealand, and the five representatives are easily distinguished. Previously, they were all included in a broadly construed Thelypteris by Allan (1961).
 Key
1Fertile laminae at least 2-pinnate-pinnatifid; lamina hairs up to 2 mm long; indusia 0.2–0.4 mm wideMacrothelypteris
Fertile laminae 1-pinnate or 1-pinnate-pinnatifid, but not more divided; lamina hairs up to 1 mm long; indusia absent or, if present, 0.4–1.2 mm wide2
2All veins free; indusia bearing capitate hairsThelypteris
At least the basal pair of veins in each pinna segment uniting with those from adjacent segments; indusia absent, glabrous or bearing acicular hairs3
3Rhizomes erect; sori lacking indusiaPneumatopteris
Rhizomes erect or creeping; sori with well-developed indusia4
4Basal pair of pinnae much shorter than those at mid-laminaChristella
Basal pair of pinnae about as long as those at mid-laminaCyclosorus
 Recognition
The Thelypteridaceae comprise mostly terrestrial ferns with undivided to almost 4-pinnate fronds, which bear hairs and sometimes also glands and scales. Characteristically the stipes, rachises and pinna bases have aerophores, and the veins are mostly free, except that the basal veins of the pinna lobes often unite below the sinus. The sori are usually round, away from the margin, and either exindusiate or protected by reniform indusia. The sporangia have a vertical annulus, and almost always produce monolete spores.
 Distribution
Widespread in tropical and sub-tropical regions, with a few species extending into temperate zones. The greatest diversity is found in Malesia, with 440 species (Holttum 1982), and the Neotropics, with another 300 species (Smith 1990). There are about 100 species in the Pacific region (Holttum 1977) and 23 in Australia (Bostock 1998). Five non-endemic genera with five species in New Zealand; none endemic.
 Biostatus
Indigenous (Non-endemic)
Number of species in New Zealand within Thelypteridaceae Pic.Serm.
CategoryNumber
Indigenous (Non-endemic)5
Total5
 Bibliography
Almeida, T.E.; Hennequin, S.; Schneider, H.; Smith, A.R.; Batista, J.A.N.; Ramalho, A.J.; Proite, K.; Salino, A. 2016: Towards a phylogenetic classification of Thelypteridaceae; additional sampling suggests alterations of neotropical taxa and further study of paleotropical genera. Molecular Phylogenetics and Evolution 94: 688–700.
Bostock, P.D. 1998: Thelypteridaceae. In: Flora of Australia. Vol. 48. 327–358.
Brownsey, P.J.; Perrie, L.R. 2011: A revised checklist of Fijian ferns and lycophytes. Telopea 13: 513–562.
Brownsey, P.J.; Perrie, L.R. 2016: Thelypteridaceae. In: Breitwieser, I; Heenan, P.B.; Wilton, A.D. Flora of New Zealand — Ferns and Lycophytes. Fascicle 15. Manaaki Whenua Press, Lincoln.
Christenhusz, M.J.M.; Chase, M.W. 2014: Trends and concepts in fern classification. Annals of Botany 113(4): 571–594.
He, L-J.; Zhang, X-C. 2012: Exploring genetic delimitation within the fern family Thelypteridaceae. Molecular Phylogenetics and Evolution 65: 757–764.
Holttum, R.E. 1971: Studies in the family Thelypteridaceae III: a new system of genera in the Old World. Blumea 19: 17–52.
Holttum, R.E. 1977: The family Thelypteridaceae in the Pacific and Australasia. Allertonia 1: 169–234.
Holttum, R.E. 1982: Thelypteridaceae. In: Flora Malesiana, Series II - Pteridophyta. Vol. 1. 334–560.
Kramer, K.U.; Green, P.S. 1990: Pteridophytes and gymnosperms. Kubitzki, K. (ed.) The Families and Genera of Vascular Plants. Vol. 1. Springer-Verlag, Berlin.
Nakamura, M. (ed.) 2008: Illustrated flora of ferns and fern allies of South Pacific Islands. National Museum of Nature and Science Book Series No. 8. Tokai University Press, Tokyo.
Pichi Sermolli, R.E.G. 1970: Fragmenta Pteridologiae II. Webbia 24: 699–722.
Smith, A.R. 1971: Systematics of the neotropical species of Thelypteris section Cyclosorus. University of California Publications in Botany 59: 1–143.
Smith, A.R. 1990: Thelypteridaceae. In: Kramer, K.U.; Green, P.S. Pteridophytes and gymnosperms. Vol. 1. In: Kubitzki, K. (ed.) The Families and Genera of Vascular Plants. Springer-Verlag, Berlin. 263–272.
Smith, A.R.; Cranfill, R.B. 2002: Intrafamilial relationships of the thelypteroid ferns (Thelypteridaceae). American Fern Journal 92: 131–149.
Smith, A.R.; Pryer, K.M.; Schuettpelz, E.; Korall, P.; Schneider, H.; Wolf, P.G. 2006: A classification for extant ferns. Taxon 55(3): 705–731.