Classification
 Subordinate Taxa
 Nomenclature
Scientific Name:
Pteridium Gled. ex Scop., Fl. Carniol. 169 (1760), nom. cons.
Synonymy:
  • = Cincinalis Gled., Syst. Pl. [Gleditsch] 290 (1764)
  • = Pteris sect. Ornithopteris J.Agardh, Recens. Spec. Pter. 45 (1839)
  • Ornithopteris (J.Agardh) J.Sm., Hist. Fil. 297 (1875) nom. illeg., non Ornithopteris Bernh. 1805
Type Taxon:
Pteridium aquilinum (L.) Kuhn
Etymology:
Diminutive of the Greek pteris (a fern).
 Description

Terrestrial ferns. Rhizomes long-creeping, bearing multicellular hairs. Fronds monomorphic. Stipes hairy. Laminae 2–5-pinnate, coriaceous, bearing non-glandular hairs; primary pinnae stalked, sometimes with reduced stipule-like basal pinnules. Veins free except for a marginal connecting vein. Sori more or less continuous around the lamina margin borne on the connecting vein, superficial; paraphyses absent. Outer indusium formed from the reflexed membranous lamina margin, opening inwards; inner indusium poorly developed or absent. Spores trilete, irregularly granulate.

 Taxonomy

Pteridium is clearly defined and forms a clade along with Paesia, Saccoloma, Histiopteris and Blotiella within Dennstaedtiaceae (Perrie et al. 2015). It is a worldwide genus variously interpreted as having a single species with two subspecies and a number of varieties (Tryon 1941; Page 1976; Tryon & Tryon 1982; Kramer 1990), or perhaps four closely related species and several subspecies (Brownsey 1989, 1998; Der et al. 2009; Thomson 2012; Zhou et al. 2014). Recent analyses of sequence data suggest that there are two major diploid clades corresponding to P. aquilinum in the Northern Hemisphere and Africa, and P. esculentum in South America, Australia, New Zealand and south-east Asia. There is also evidence for two allotetraploid species – P. semihastatum in northern Australia and south-east Asia, and P. caudatum in Central and South America (Thomson & Alonso-Amelot 2002; Der et al. 2009; Zhou et al. 2014). However, some authors have continued to recognise additional species in South America (Schwartsburd et al. 2014) and China (Liao et al. 2013).

 Recognition

Pteridium can be recognised by its long-creeping rhizomes, highly divided laminae bearing non-glandular hairs, and sori that are more or less continuous around the lamina margins protected by the inrolled lamina margin and a poorly developed inner indusium.

 Distribution

A subcosmopolitan genus interpreted here as having four closely related species and several subspecies. There are two species in Australia (Brownsey 1989, 1998) and one in the Pacific. One non-endemic species in New Zealand.

 Biostatus
Indigenous (Non-endemic)
Number of species in New Zealand within Pteridium Gled. ex Scop.
CategoryNumber
Indigenous (Non-endemic)1
Total1
 Cytology

The base chromosome number in Pteridium is x = 26 (Brownsey 1983; Kramer 1990).

 Bibliography
Agardh, J.G. 1839: Recensio specierum generis Pteridis. Berling, Lund.
Brownsey, P.J. 1983: Polyploidy and aneuploidy in Hypolepis, and the evolution of the Dennstaedtiales. American Fern Journal 73: 97–108.
Brownsey, P.J. 1989: The taxonomy of bracken (Pteridium: Dennstaedtiaceae) in Australia. Australian Systematic Botany 2: 113–128.
Brownsey, P.J. 1998: Dennstaedtiaceae. In: Flora of Australia. Vol. 48. 214–228.
Brownsey, P.J.; Perrie, L.R. 2018: Dennstaedtiaceae. In: Breitwieser, I.; Wilton, A.D. (ed.) Flora of New Zealand — Ferns and Lycophytes. Fascicle 19. Manaaki Whenua Press, Lincoln.
Christenhusz, M.J.M.; Zhang, X.-C.; Schneider, H. 2011: A linear sequence of extant families and genera of lycophytes and ferns. Phytotaxa 19: 7–54.
Der, J.P.; Thomson, J.A.; Stratford, J.K.; Wolf P.G. 2009: Global chloroplast phylogeny and biogeography of bracken (Pteridium; Dennstaedtiaceae). American Journal of Botany 96: 1041–1049.
Gleditsch, J.G. 1764: Systema Plantarum a staminum situ. Haude & Spener, Berlin.
Kramer, K.U. 1990: Dennstaedtiaceae. 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.
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.
Liao, W.; Ding, M.; Wu, Z.; Prado, J. 2013: Pteridium. In: Zhengyi, W.; Raven, P.H.; Deyuan, H. (ed.) Flora of China. Lycopodiaceae through Polypodiaceae. Vol. 2–3. Science Press, Beijing.
Page, C.N. 1976: The taxonomy and phytogeography of bracken – a review. Botanical Journal of the Linnean Society 73: 1–34.
Perrie, L.R.; Shepherd, L.D.; Brownsey, P.J. 2015: An expanded phylogeny of the Dennstaedtiaceae ferns: Oenotrichia falls within a non-monophyletic Dennstaedtia, and Saccoloma is polyphyletic. Australian Systematic Botany 28: 256–264.
Schwartsburd, P.B; de Moraes, P.L.R.; Lopes-Mattos, K.L.B. 2014: Recognition of two morpho-types in eastern South American brackens (Pteridium – Dennstaedtiaceae – Polypodiopsida). Phytotaxa 170: 103–117.
Scopoli, J.A. 1760: Flora Carniolica. Joannis Thomae Trattner, Vienna.
Smith, J. 1875: Historia Filicum; an exposition of the nature, number, and organography of ferns. Macmillan, London.
Thomson, J.A. 2012: Taxonomic status of diploid Southern hemisphere brackens (Pteridium: Dennstaedtiaceae). Telopea 14: 43–48.
Thomson, J.A; Alonso-Amelot, M.E. 2002: Clarification of the taxonomic status and relationships of Pteridium caudatum (Dennstaedtiaceae) in Central and South America. Botanical Journal of the Linnean Society 140: 237–248.
Tryon, R.M. 1941: A revision of the genus Pteridium. Rhodora; Journal of the New England Botanical Club. 43: 1–31, 37–67.
Tryon, R.M.; Tryon, A.F. 1982: Ferns and allied plants. Springer-Verlag, New York.
Zhou, S.; Dong, W.; Chen, X.; Zhang, X.; Wen, J.; Schneider, H. 2014: How many species of bracken (Pteridium) are there? Assessing the Chinese brackens using molecular evidence. Taxon 63: 509–521.