Polypodiineae is a suborder of ferns in the order Polypodiales. It is equivalent to the clade eupolypods I in earlier systems,[1][2] and to the very broadly defined family Polypodiaceae in the classification of Christenhusz & Chase (2014).[3] It probably diverged from the suborder Aspleniineae (eupolypods II) during the mid-Cretaceous. The divergence is supported by both molecular data and an often overlooked morphological characteristic which lies in the vasculature of the petiole. Most species that make up the suborder have three vascular bundles. The only exceptions are the grammitid ferns which have one, and the genus Hypodematium which has two. This differs from eupolypods II which mostly have two vascular bundles (except the well-nested blechnoid ferns which generally have at least three).[4]
| Polypodiineae | |
|---|---|
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| Common Polypody, Polypodium vulgare | |
Scientific classification 
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Division: | Polypodiophyta |
| Class: | Polypodiopsida |
| Order: | Polypodiales |
| Suborder: | Polypodiineae Dumort.[1] |
| Families[1] | |
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Taxonomy
editIn the Pteridophyte Phylogeny Group classification of 2016 (PPG I), the group is treated as the suborder Polypodiineae, and divided into 11 families.[1] Alternatively, it may be treated as a single, very broadly circumscribed family Polypodiaceae sensu lato, which is then divided into subfamilies.[3] The relationship between the two approaches is shown in the table below.
| PPG I[1] | Christenhusz & Chase (2014)[3] |
|---|---|
| Suborder Polypodiineae Dumort. | Family Polypodiaceae J.Presl & C.Presl |
| Family Didymochlaenaceae Ching ex Li Bing Zhang & Liang Zhang | Subfamily Didymochlaenoideae Christenh. |
| Family Hypodematiaceae Ching | Subfamily Hypodematioideae Christenh. |
| Family Dryopteridaceae Herter | Subfamily Dryopteridoideae Link |
| Family Nephrolepidaceae Pic.Serm. | Subfamily Lomariopsidoideae Crabbe, Jermy & Mickel |
| Family Lomariopsidaceae Alston | |
| Family Tectariaceae Panigrahi | Subfamily Tectarioideae B.K.Nayar |
| Family Oleandraceae Ching ex Pic.Serm. | Subfamily Oleandroideae Crabbe, Jermy & Mickel |
| Family Davalliaceae M.R.Schomb. | Subfamily Davallioideae Hook. |
| Family Polypodiaceae J.Presl & C.Presl | Subfamily Polypodioideae B.K.Nayar |
Phylogeny
editThe Polypodiineae is one of two major groups of eupolypod families, treated as suborders, within the order Polypodiales. In 2016, the Pteridophyte Phylogeny Group published a consensus cladogram, based on "numerous phylogenetic studies" between 2001 and 2015. The location of the Polypodiineae within the order Polypodiales in this cladogram is:[1]
| Polypodiales |
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To the level of families, the subtree for the Polypodiineae is:[1]
| Polypodiineae |
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Of the 108 genera in the suborder, 91 (84%) are placed in two families, Dryopteridaceae and Polypodiaceae.[1]
References
edit- ^ a b c d e f g h PPG I (2016). "A community-derived classification for extant lycophytes and ferns". Journal of Systematics and Evolution. 54 (6): 563–603. doi:10.1111/jse.12229. S2CID 39980610.
- ^ Alan R. Smith; Kathleen M. Pryer; Eric Schuettpelz; Petra Korall; Harald Schneider; Paul G. Wolf (2006). "A classification for extant ferns" (PDF). Taxon. 55 (3): 705–731. doi:10.2307/25065646. JSTOR 25065646. Archived from the original (PDF) on 2008-02-26.
- ^ a b c Christenhusz, Maarten J. M.; Chase, Mark W. (13 February 2014). "Trends and concepts in fern classification". Annals of Botany. 113 (4): 571–594. doi:10.1093/aob/mct299. PMC 3936591. PMID 24532607.
- ^ S. Blair Hedges; Sudhir Kumar (2009). The Timetree of Life. US: Oxford University Press. pp. 154–156. ISBN 9780191560156. Retrieved 23 August 2011.