Adder tongues
| Adder tongues | ||||||||||||
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Common adder's tongue ( Ophioglossum vulgatum ) |
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| Ophioglossum | ||||||||||||
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The adder tongues ( Ophioglossum ) are a genus of ferns from the family of the adder tongue plants (Ophioglossaceae).
description
Like all plants of the family, the adder tongues have one or a few basal leaves that arise from a short, underground stem. The leaves are divided to the base or at least far down into two sections, a flat, sterile "blade", the trophophyll , which is usually referred to as "the leaf", and a fertile part, the sporophyll .
The trophophyll in the adder tongues is always undivided and with entire margins. In terms of shape, it is tongue-shaped, lanceolate, to heart-shaped. Its base encompasses the sporophyll, so that at first glance the two leaf parts often only appear to separate far above the ground. The flat part of the trophophyll can be seated or pedicled. Its size varies considerably with the different species.
The net-like nerve of the trophophylls seems to indicate that the adder tongues are more of a derived than an original group of ferns.
The sporophyll is not always present and always has a long stalk. The sporangia are arranged on it in two vertical rows and laterally fused, so that it looks as if they were sunk into the sporophyll. The latter is narrowly linear and ends in most species more or less pointed.
In most species in the temperate latitudes, only a single leaf is formed per year, in tropical representatives of the genus sometimes up to five.
Distribution and location requirements
The genus is distributed worldwide, with most species occurring in the tropics and subtropics .
All but two species of adder tongues grow on moist to wet soil on grassland. They are likely to be overlooked often because, when sterile, they resemble the cotyledons of a monocot .
The two non-soil species mentioned are Ophioglossum pendulum and Ophioglossum palmatum . These grow epiphytically and also differ in their habitus a lot from the other species, which is why they are often separated out as Ophioderma pendula or Cheiroglossa palmata in their own, monotypical genera.
species
The genus comprises between 20 and 50 species worldwide.
European species
There are four types in Europe :
- Ophioglossum azoricum C. Presl : It occurs in the Azores, Canaries, Madeira, Portugal, Spain, France, Great Britain, Iceland, Ireland, Italy, Corsica and Poland.
- Ophioglossum lusitanicum L .: It occurs in the Azores, Canaries and Madeira, in Morocco, Algeria, Tunisia, Tanzania, Uganda, in Portugal, Spain, France, Great Britain, Italy, Croatia, Greece, Albania, Cyprus, Vodreasia, Azerbaijan and Georgia in front.
- Ophioglossum polyphyllum A. Braun , occurs in Africa and Southwest Asia, but also on the Canary Islands.
- Common adder tongue ( Ophioglossum vulgatum L. ), occurs in almost all of Europe, North America, Asia, Australia, and Africa.
Other types (selection)
- Ophioglossum austroasiaticum M. Nishida : It occurs in Borneo and Taiwan.
- Ophioglossum californicum Prantl : It occurs in California and Mexico.
- Ophioglossum costatum R. Br .: It occurs in tropical and southern Africa, Madagascar, the Comoros, India, Sri Lanka, Thailand, Indonesia, the Philippines, Australia and French Polynesia.
- Ophioglossum crotalophoroides Walter : It occurs in North, Central and South America and in the Caribbean.
- Ophioglossum engelmannii Prantl : It is found in the United States, southern Mexico, and Honduras and Costa Rica.
- Ophioglossum malviae M.Patel & MNReddy , from the Indian Western Ghats is considered the smallest terrestrial vascular spore plant in the world. It was first described in 2018.
- Ophioglossum nudicaule L. f. : It occurs in northern India, in Nepal, Sichuan, Xizang and Yunnan, also in North, Central and South America, in the Caribbean, in Africa and on islands in the Pacific.
- Ophioglossum oblongum H.G. Zhou & H. Li : It occurs in Guangxi.
- Ophioglossum palmatum L. (Syn .: Cheiroglossa palmata (L.) C. Presl ), occurs in Central and South America as well as in Madagascar.
- Ophioglossum pendulum L. (Syn .: Ophioderma pendula (L.) C. Presl ): It occurs in tropical and subtropical Asia, in West Africa, Australia and Hawaii.
- Ophioglossum petiolatum Hooker : It occurs in tropical and subtropical Asia, in Australia, New Zealand, in North America, also in the Caribbean, in Mexico, in northern South America and on islands in the Pacific.
- Ophioglossum pusillum Rafinesque : It is found in Alaska, Canada, and the United States.
- Ophioglossum reticulatum L .: It occurs in Africa, Madagascar, South America, Korea and China at altitudes between 1100 and 4000 meters above sea level. An occurrence in Madeira is questionable.
- Ophioglossum thermale Komarov : It occurs in Kamchatka, Japan, Korea, Taiwan and China and here especially near thermal springs.
- Ophioglossum yongrenense Ching ex ZR He & WM Chu : It occurs only in Yunnan at altitudes around 2000 meters above sea level.
Others
The number of chromosomes in the adder's tongues is remarkably high. The South Asian species Ophioglossum reticulatum even has the highest number of chromosomes in the entire plant kingdom with 2n = 1260.
All types of adder's tongue are mycotrophic , i.e. more or less dependent on living together with fungi. For example, the roots lack the root hairs, which suggests that mycorrhizal fungi have taken over their function. Furthermore, the underground prothallium usually remains chlorophyll-free and therefore cannot survive on its own. Finally, in some species the sporophyll is almost entirely reduced.
Sources and further information
literature
- Franz Fukarek: Urania plant kingdom . Volume 2: mosses, ferns, naked plants. Urania-Verlag, Leipzig 1992, ISBN 3-332-00495-6 .
- Wolfgang Frey , Jan-Peter Frahm , Eberhard Fischer, Wolfram Lobin: Small cryptogam flora. Volume IV: The Moss and Fern Plants of Europe. Gustav Fischer, Stuttgart, Jena, New York 1995, ISBN 3-437-30756-8 .
- Warren H. Wagner Jr., Florence S. Wagner: Ophioglossum. In: Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico . Volume 2: Pteridophytes and Gymnosperms . Oxford University Press, New York / Oxford a. a. 1993, ISBN 0-19-508242-7 , pp. 102–105 (English, limited preview in Google Book Search). , online (English).
- Werner Rothmaler , John Robert Akeroyd: Ophioglossum L. In: TG Tutin, NA Burges, AO Chater, JR Edmondson, VH Heywood, DM Moore, DH Valentine, SM Walters, DA Webb (eds.): Flora Europaea . 2nd, revised edition. Volume 1: Psilotaceae to Platanaceae . Cambridge University Press, Cambridge / New York / Melbourne 1993, ISBN 0-521-41007-X , pp. 9–10 (English, limited preview in Google Book Search).
Individual evidence
- ↑ a b c Christenhusz, M. & Raab-Straube, E. von (2013): Lycopodiophytina. - In: Euro + Med Plantbase - the information resource for Euro-Mediterranean plant diversity. Datasheet Ophioglossum In: Euro + Med Plantbase - the information resource for Euro-Mediterranean plant diversity.
- ↑ a b c Ophioglossum in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved February 16, 2019.
- ↑ a b c d e f g h Quanru Liu & Norio Sahashi: Ophioglossum Linnaeus. - Same text online as the printed work , In: Wu Zheng-yi, Peter H. Raven, Deyuan Hong (Ed.): Flora of China. Volume 2-3: Ophioglossaceae. Science Press and Missouri Botanical Garden Press, Beijing and St. Louis 2010
- ↑ a b c d e Warren H. Wagner Jr., Florence S. Wagner: Ophioglossum Linnaeus. In: Flora of North America, vol. 2. [1] .
- ↑ Mitesh Patel and Mandadi Narsimha Reddy. 2018. Discovery of the World's Smallest Terrestrial Pteridophyte. Scientific Reports. 8, Article number: 5911. DOI: 10.1038 / s41598-018-24135-2
