Dicksoniaceae

Dicksoniaceae is a group of tropical, subtropical and warm temperate ferns, treated as a family in the Pteridophyte Phylogeny Group classification of 2016 (PPG I),[1] and counting 30-40 species.[2] Alternatively, the family may be sunk into a very broadly defined family Cyatheaceae sensu lato as the subfamily Dicksonioideae.[3] Most of the genera in the family are terrestrial ferns or have very short trunks compared to tree ferns of the family Cyatheaceae sensu stricto. However, some of the larger species can reach several metres in height. A number of others are epiphytes. They are found mostly in tropical regions in the Southern Hemisphere, as far south as southern New Zealand. Larger tree ferns in the genus Cibotium were formerly included in Dicksoniaceae, but are now segregated as the family Cibotiaceae.

Dicksoniaceae
Temporal range: Early Cretaceous–Recent
Calochlaena dubia.jpg
Calochlaena dubia
Scientific classification e
Kingdom: Plantae
Clade: Tracheophytes
Division: Polypodiophyta
Class: Polypodiopsida
Order: Cyatheales
Family: Dicksoniaceae
Bower, nom. cons.
Genera

DescriptionEdit

Species in the family are generally characterized by large pinnate fronds, 1–4 m long. The family includes several species of tree ferns, which grow a single trunk, notably the species in Dicksonia. All members of the family have long, tapering hairs composed of cells arranged end to end, unlike the scales characteristic of the Cyatheaceae s.l.

EvolutionEdit

The family is thought to have arisen in the Early Cretaceous, based on molecular evidence. Lophosoria is known from fossil spores and leaf fragments from South America dating to the Aptian. The oldest fossil of Dicksonia is known from the Eocene of Antarctica.[4] The widespread Jurassic-Cretaceous herbaceous fern genus Coniopteris has historically been assigned to this family, but cladistic analysis suggests that it is more closely related to the Polypodiales.[5] Relationships of the three living genera, after.[4]


Dicksoniaceae

Calochlaena

Lophosoria

Dicksonia

GeneraEdit

Only three extant genera are recognised in this monophyletic family:[6]

Image Genus Living species
  Calochlaena (Maxon) M.D.Turner & R.A.White
  Dicksonia L'Hér.
  Lophosoria C.Presl

ReferencesEdit

  1. ^ 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.
  2. ^ Scaly Tree Ferns Have Slow and Steady Diversification
  3. ^ Christenhusz, Maarten J.M. & Chase, Mark W. (2014). "Trends and concepts in fern classification". Annals of Botany. 113 (9): 571–594. doi:10.1093/aob/mct299. PMC 3936591. PMID 24532607.
  4. ^ a b Noben, Sarah; Kessler, Michael; Quandt, Dietmar; Weigand, Anna; Wicke, Susann; Krug, Michael; Lehnert, Marcus (2017-07-11). "Biogeography of the Gondwanan tree fern family Dicksoniaceae-A tale of vicariance, dispersal and extinction". Journal of Biogeography. 44 (11): 2648–2659. doi:10.1111/jbi.13056. ISSN 0305-0270. S2CID 90175188.
  5. ^ Li, Chunxiang; Miao, Xinyuan; Zhang, Li-Bing; Ma, Junye; Hao, Jiasheng (January 2020). "Re-evaluation of the systematic position of the Jurassic–Early Cretaceous fern genus Coniopteris". Cretaceous Research. 105: 104136. doi:10.1016/j.cretres.2019.04.007. S2CID 146355798.
  6. ^ Hassler, Michael & Schmitt, Bernd (November 2019). "Dicksoniaceae". Checklist of Ferns and Lycophytes of the World. 8.11. Retrieved 2019-11-25.

External linksEdit