Biology:Osmunda

Short description: Genus of ferns

Osmunda Temporal range: Paleocene–recent PreЄ Є O S D C P T J K Pg N
Osmunda regalis
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Division:	Polypodiophyta
Class:	Polypodiopsida
Order:	Osmundales
Family:	Osmundaceae
Genus:	Osmunda L.
Type species
Osmunda regalis L.
Species
See text
Synonyms
Aphyllocalpa Lagasca, Garcia & Clemente Struthiopteris Bernhardi

Young plant

Osmunda is a genus of primarily temperate-zone ferns of family Osmundaceae. Five to ten species have been listed for this genus.

Description

Completely dimorphic fronds or pinnae (hemidimorphic), green photosynthetic sterile fronds, and non-photosynthetic spore-bearing fertile pinnae, with large, naked sporangia. Because of the large mass of sporangia that ripen uniformly at the same time to a showy golden color, the ferns look as if they are in flower, and so this genus is sometimes called the "flowering ferns".

Taxonomy

Osmunda, the type genus of the fern order, Osmundales has historically been the largest genus in the family Osmundaceae. Smith et al. (2006), who carried out the first higher-level pteridophyte classification published in the molecular phylogenetic era, described three genera in that family, namely Osmunda, Leptopteris, and Todea. The genus has also been treated historically as consisting of a number of subgroups, generally subgenera, Osmunda (3 species), Osmundastrum (2 species), and Plenasium (3–4 species). However, there was suspicion that the genus was not monophyletic.

The publication of a detailed phylogeny of the family by Metzgar et al. in 2008 showed that Osmunda as circumscribed was paraphyletic and that Osmunda cinnamomea, despite its morphological similarity to Osmunda claytoniana, was sister to the rest of the family, and resurrected the segregate genus Osmundastrum, by elevating it from subgenus, to contain it and render Osmunda monophyletic. The phylogeny of Osmunda is shown in the following cladograms.

External phylogeny	Internal phylogeny
Osmundaceae   Osmundastrum 1 species         Todea 2 species     Leptopteris 6 species     Osmunda   subgenus Claytosmunda 1 species       subgenus Plenasium 4 species     subgenus Osmunda 4 species	Osmunda     O. hybrida     O. regalis         O. spectabilis       O. japonica     O. lancea

A number of authors have proposed elevating the subgenera to separate genus level, In 2016 the Pteridophyte Phylogeny Group (PPG) classification split Osmunda further by elevating its subgenera to genera as Claytosmunda and Plenasium, leaving only the species originally included in subgenus Osmunda.

• O. abyssinica (Kuhn 1879) Bobrov
• O. acuta (Burm.fil. 1768) Fraser-Jenk.
• †O. chengii Bomfleur, Grimm & McLoughlin [Osmunda claytoniites Phipps, Taylor & Taylor non Graham 1963]
• O. herbacea Copeland
• O. hybrida Tsutsumi et al.
• O. × intermedia {O. lancea × O. japonica}
• O. japonica Thunberg (Japanese flowering fern)
• O. lancea Thunberg (Japanese lancea flowering fern)
• O. x mildei {O. angustifolia × O. japonica}
• O. piresii Brade 1965
• O. regalis L. (Old World royal fern)
• O. × ruggii {O. claytoniana × O. spectabilis}
• O. spectabilis Willdenow (American royal fern)
• †O. wehrii Miller (Middle Miocene, Washington state)

Etymology

The derivation of the genus name is uncertain. A common theory is that Osmunda derives from Osmunder, a Saxon name for the god Thor. Other explanations propose that it is from Middle English and Middle French words for a type of fern, or mention an English folk tale of a boatman named Osmund hiding his wife and children in a patch of royal fern during the Danish invasion.

Ecology

O. japonica, O. × intermedia, and O. lancea

Osmunda species are used as food plants by the larvae of some Lepidoptera species including the engrailed.

One of the species, the cinnamon fern (Osmundastrum cinnamomeum) forms huge clonal colonies in swamp areas. These ferns form massive rootstocks with densely matted, wiry roots. This root mass is an excellent substrate for many epiphytal plants. They are often harvested as osmundine and used horticulturally, especially in propagating and growing orchids.

Bibliography

• Botanical Journal of the Linnean Society 161 (2): 122–127. doi:10.1111/j.1095-8339.2009.01002.x. 
• Christenhusz, M. J. M.; Zhang, X. C.; Schneider, H. (18 February 2011). "A linear sequence of extant families and genera of lycophytes and ferns". Phytotaxa 19 (1): 7. doi:10.11646/phytotaxa.19.1.2. 
• Christenhusz, Maarten J.M.; Chase, Mark W. (2014). "Trends and concepts in fern classification". Annals of Botany 113 (4): 571–594. doi:10.1093/aob/mct299. PMID 24532607. 
• Christenhusz, Maarten JM; Byng, J. W. (2016). "The number of known plants species in the world and its annual increase". Phytotaxa 261 (3): 201–217. doi:10.11646/phytotaxa.261.3.1. http://biotaxa.org/Phytotaxa/article/download/phytotaxa.261.3.1/20598. 
• Lehtonen, Samuli (2011). "Towards Resolving the Complete Fern Tree of Life". PLoS ONE 6 (10): e24851. doi:10.1371/journal.pone.0024851. PMID 22022365. Bibcode: 2011PLoSO...624851L. 
• Metzgar, Jordan S.; Skog, Judith E.; Zimmer, Elizabeth A.; Pryer, Kathleen M. (1 March 2008). "The Paraphyly of Osmunda is Confirmed by Phylogenetic Analyses of Seven Plastid Loci". Systematic Botany 33 (1): 31–36. doi:10.1600/036364408783887528. https://www.researchgate.net/publication/228711234. 
• Pryer, Kathleen M.; Schneider, Harald; Smith, Alan R.; Cranfill, Raymond; Wolf, Paul G.; Hunt, Jeffrey S.; Sipes, Sedonia D. (2001). "Horsetails and ferns are a monophyletic group and the closest living relatives to seed plants". Nature 409 (6820): 618–622. doi:10.1038/35054555. PMID 11214320. Bibcode: 2001Natur.409..618S. 
• Pteridophyte Phylogeny Group (November 2016). "A community-derived classification for extant lycophytes and ferns". Journal of Systematics and Evolution 54 (6): 563–603. doi:10.1111/jse.12229. 
• Ranker, Tom A.; Haufler, Christopher H., eds (2008). Biology and Evolution of Ferns and Lycophytes. Cambridge University Press. ISBN 978-0-521-87411-3. https://books.google.com/books?id=js9JnwEACAAJ. 
• Schneider, Harald; Smith, Alan R.; Pryer, Kathleen M. (1 July 2009). "Is Morphology Really at Odds with Molecules in Estimating Fern Phylogeny?". Systematic Botany 34 (3): 455–475. doi:10.1600/036364409789271209. 
• Smith, Alan R.; Kathleen M. Pryer; Eric Schuettpelz; Petra Korall; Harald Schneider; Paul G. Wolf (2006). "A classification for extant ferns". Taxon 55 (3): 705–731. doi:10.2307/25065646. https://www.idigbio.org/wiki/images/9/95/Smith_et_al_2006.pdf. 
• Smith, Alan R.; Pryer, Kathleen M.; Schuettpelz, Eric; Korall, Petra; Schneider, Harald; Wolf, Paul G. (24 April 2022). Fern classification. pp. 417–467. http://pryerlab.biology.duke.edu/uploads/media_items/smith-et-al-2008.original.pdf. , in (Ranker Haufler)
• Phipps, C.J., Taylor, T.N., Taylor, E.L., Cuneo, N.R., Boucher, L.D., and Yao, X. (1998). Osmunda (Osmundaceae) from the Triassic of Antarctica: An example of evolutionary stasis. American Journal of Botany 85: 888-895

External links

• Germplasm Resources Information Network: Osmunda
• Flora of North America: Osmunda
• Species list for Osmunda
• http://data.gbif.org/species/browse/taxon/13191108

Wikidata ☰ Q1427328 entry