Class
Subclass
Order
Family
Classification
Subordinate Taxa
Nomenclature
Scientific Name:
Pteris L., Sp. Pl. 1073 (1753)
Type Taxon:
Pteris longifolia
Etymology:
Description
Terrestrial or rupestral ferns. Rhizomes erect to short-creeping, scaly. Rhizome scales non-clathrate, narrowly ovate, attached at the base, concolorous or with dark centres and pale margins, pale brown to blackish. Fronds monomorphic. Stipes and rachises pale brown to red-brown, or occasionally green. Laminae 1-pinnate to 4-pinnate-pinnatifid (NZ) or 5-pinnate (not NZ), sometimes pedate (NZ) or palmate (not NZ); herbaceous or coriaceous, glabrous or hairy and/or scaly. Pinnae and ultimate lamina segments not articulated to rachis and costae. Veins free or reticulate, the areolae without free included veinlets. Sori extending along the margins; paraphyses present; sori protected by the membranous, reflexed, lamina margin. Spores trilete, lacking chlorophyll; perispores coarsely ridged, tuberculate or reticulate with an equatorial flange.
Taxonomy
A genus of c. 250 species, included in the subfamily Pteridoideae along with Anogramma (PPG 1 2016).
There is no modern monograph of Pteris world-wide, and no clear indication of natural subgeneric groups based on morphology. Phylogenetic analysis by Zhang et al. (2015), based on six plastid loci, indicated that the genus is monophyletic, with 15 different clades recognised world-wide. A more extensive survey of 178 species by Zhang & Zhang (2018), using one nuclear and eight plastid genes, recovered 16 clades. Based on this study, Zhang & Zhang recognised 15 sections in three subgenera, one of them monotypic. Four of the five indigenous New Zealand species fell into subgenus Campteria section Tripedipteris. One of the subclades within this section comprises seven Oceanian species with anastomosing veins, including P. carsei (as P. comans), P. macilenta and P. saxatilis from New Zealand; P. epaleata (as P. comans) from Australia and New Zealand; P. microptera Mett. ex Kuhn from Lord Howe Island; and two other Pacific species. The fifth indigenous species, P. tremula, forms a small clade with the South American P. chilensis Desv. in which the laminae are 3–4-pinnatifid and the veins free. This is subgenus Campteria, section Tremulae.
Allan (1961) recognised three species in New Zealand – P. comans G.Forst., P. macilenta and P. tremula, with P. saxatilis treated as a variety of P. macilenta. Walker (1962) investigated the species with anastomosing veins cytologically and reported that P. comans and P. saxatilis were diploid species with 2n = 58, and that P. macilenta was a tetraploid species with 2n = c. 116. The genus in New Zealand was the subject of an unpublished Ph.D. thesis by Braggins (1975). He suggested that the New Zealand plant treated by previous authors as P. comans was an endemic species distinct from other members of the complex, and it has subsequently been described as P. carsei (Brownsey et al. 2020). Braggins (1975) also suggested that the type of P. macilenta was actually a specimen of what was being called P. saxatilis, and that the correct names for these two species should be P. pendula and P. macilenta, respectively. However, reassessment of potential type material in P has shown that the only original material is, in fact, a specimen of P. macilenta, and that the names P. macilenta and P. saxatilis should be used in their traditional sense (Brownsey & Perrie 2020).
Following the recognition of P. carsei as a New Zealand endemic, distinct from P. comans sens. str. in the tropical Pacific, Ohlsen et al. (2020) described Australian plants, previously referred to P. comans, as P. epaleata. This species extends to New Zealand, with a few populations known from southern Fiordland.
Several species of Pteris are established in the horticultural trade and have become naturalised around the world. Seven naturalised species, P. argyraea, P. cretica, P. dentata, P. multifida, P. pacifica, P. parkeri and P. vittata, have been added to the New Zealand flora in the last 40 years.
Key
| 1 | Lamina veins anastomosing | 2 |
| Lamina veins free | 5 | |
| 2 | Scales absent on rachises and pinna costae, or if present, very narrow and hair-like | epaleata |
| Scales present on rachises and pinna costae, ovate, not hair-like | 3 | |
| 3 | 1–2 pairs of basal basiscopic secondary pinnae on lowermost primary pinnae greatly extended; all except 1–2 secondary pinnae on proximal primary pinnae adnate to costae | carsei |
| Basal basiscopic pinnae on lowermost primary pinnae not greatly extended; most secondary pinnae on proximal primary pinnae distinctly stalked | 4 | |
| 4 | Primary and secondary pinnae very widely spaced; laminae 100–500 mm long, 35–300 mm wide; secondary pinnae 12–85 mm long, 6–35 mm wide; tertiary pinnae 4–24 mm long and 2–12 mm wide; exospore size 32–37 μm in diameter* | saxatilis |
| Primary and secondary pinnae less widely spaced; laminae 130–900 mm long, 60–750 mm wide; secondary pinnae 16–290 mm long, 8–160 mm wide; tertiary pinnae 9–85 mm long, 3–60 mm wide; exospore size 41–46 μm in diameter* | macilenta | |
| 5 | Primary pinnae bicolorous, with prominent white or yellow-green bands along their centres | 6 |
| Primary pinnae concolorous, lacking prominent white or yellow-green bands along their centres | 7 | |
| 6 | Distal primary pinnae deeply pinnatifid, with white bands along their centres | argyraea |
| Distal primary pinnae undivided, with yellow-green bands along their centres | parkeri | |
| 7 | Laminae 1–2-pinnate at base | 8 |
| Laminae 3–4-pinnate at base | 10 | |
| 8 | Proximal primary pinnae undivided | vittata |
| Proximal primary pinnae divided or forked | 9 | |
| 9 | Proximal primary pinnae with at least one pair of secondary pinnae arising on both sides | multifida |
| Proximal primary pinnae with 1–3 secondary pinnae on basiscopic side only | cretica | |
| 10 | Laminae 1-pinnate-pinnatifid at their mid-point; spine-like outgrowths on adaxial surface of costae of primary pinnae | 11 |
| Lamina usually 2-pinnate-pinnatifid at their mid-point; spine-like outgrowths absent from costae of primary pinnae | tremula | |
| 11 | Secondary pinnae on primary pinnae at mid-point of lamina <12 mm long, all about equal in length, decreasing only slightly distally | pacifica |
| Secondary pinnae on primary pinnae at mid-point of lamina >12 mm long, decreasing markedly in length distally | dentata |
* Exospore measurements are the range of mean values for sampled individuals.
Recognition
In New Zealand, species of Pteris are medium to large ferns with 1-pinnate to 4-pinnate-pinnatifid glabrous laminae, anastomosing or free veins, and the sori continuous along the pinna margins, protected by membranous inrolled pinna margins. The spores are trilete, and coarsely tuberculate or cristate (Large & Braggins 1991).
Distribution
Pteris is world-wide in distribution, occurring in tropical and temperate regions of all continents except Antarctica (Zhang et al. 2015). Its greatest diversity is in eastern Asia, with 78 species recorded in China alone (Liao et al. 2013); six indigenous and one naturalised species in southern Africa (Crouch et al. 2011), eight indigenous and two naturalised species in Australia (Kramer & McCarthy 1998), and 18 in the south-west Pacific (Nakamura 2008). Twelve species in New Zealand; five indigenous and seven naturalised, three endemic.
Biostatus
Indigenous (Non-endemic)
| Category | Number |
|---|---|
| Indigenous (Endemic) | 3 |
| Indigenous (Non-endemic) | 2 |
| Exotic: Fully Naturalised | 3 |
| Exotic: Casual | 4 |
| Total | 12 |
Cytology
The base chromosome number in Pteris is x = 29 with an extensive polyploid series from diploid to at least octoploid, with many hybrids and apomictic species also reported (Walker 1962; Tindale & Roy 2002).
Bibliography
Braggins, J.E. 1975: Studies on the New Zealand, and some related, species of Pteris L. Unpublished PhD thesis, University of Auckland, New Zealand.
Brownsey, P.J.; Braggins, J.; Perrie, L.R. 2020: Pteris carsei (Pteridaceae), a new endemic fern from New Zealand previously treated as P. comans G.Forst. New Zealand Journal of Botany 58(3): 214–222.
Brownsey, P.J.; Perrie, L.R. 2020: Taxonomic notes on the New Zealand flora: lectotypes in Pteridaceae. New Zealand Journal of Botany 58(3): 245–254.
Brownsey, P.J.; Perrie, L.R. 2021: Pteridaceae. In: Breitwieser, I. (ed.) Flora of New Zealand — Ferns and Lycophytes. Fascicle 30. Manaaki Whenua Press, Lincoln.
Crouch, N.R.; Klopper, R.R.; Burrows, J.E.; Burrows, S.M. 2011: Ferns of southern Africa. A comprehensive guide. Struik Nature, Cape Town.
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.
Kramer, K.U.; McCarthy, P.M. 1998: Pteridaceae. In: Flora of Australia. Vol. 48. 241–248.
Large, M.F.; Braggins, J.E. 1991: Spore atlas of New Zealand ferns and fern allies. SIR Publishing, Wellington.
Liao, W.; Ding, M.; Wu, Z.; Wu, S.; Prado, J.; Gilbert, M.G. 2013: Pteris. In: Zhengyi, W.; Raven, P.H.; Deyuan, H. (ed.) Flora of China. Lycopodiaceae through Polypodiaceae. Vol. 2–3. Science Press, Beijing.
Linnaeus, C. 1753: Species Plantarum. Impensis Laurentii Salvii, Stockholm.
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.
Ohlsen, D.J.; Brownsey, P.J.; Shepherd, L.D.; Perrie, L.R.; May, E.L.; Chen, C.-W.; Bayly, M.J. 2020: Pteris epaleata, a new fern species from Australia and New Zealand segregated from P. comans (Pteridaceae). Muelleria 39: 17–26.
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.
Tindale, M.D.; Roy, S.K. 2002: A cytotaxonomic survey of the Pteridophyta of Australia. Australian Systematic Botany 15: 839–937.
Walker, T.G. 1962: Cytology and evolution in the fern genus Pteris. Evolution 16: 27–43.
Zhang, L.; Rothfels, C.J.; Ebihara, A.; Schuettpelz, E.; Le Péchon, T.; Kamau, P.; He, H.; Zhou, X-M.; Prado, J.; Field, A.; Yatskievych, G.; Gao, X-F., Zhang, L.B. 2015: A global plastid phylogeny of the brake fern genus Pteris (Pteridaceae) and related genera in the Pteridoideae. Cladistics 31: 406–423.
Zhang, L.; Zhang, L.-B. 2018: Phylogeny and systematics of the brake fern genus Pteris (Pteridaceae) based on molecular (plastid and nuclear) and morphological evidence. Molecular Phylogenetics and Evolution 118: 265–285.
