Aneura mirabilis | |
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Scientific classification | |
Kingdom: | Plantae |
Division: | Marchantiophyta |
Class: | Jungermanniopsida |
Order: | Metzgeriales |
Family: | Aneuraceae |
Genus: | Aneura |
Species: | A. mirabilis |
Binomial name | |
Aneura mirabilis (Malmb.) Wickett et Goffinet [1] | |
Synonyms [1] | |
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Aneura mirabilis is a parasitic species of liverworts in the family Aneuraceae. [2] It was first described in 1933, as Cryptothallus mirabilis. [3] Plants of this species are white as a result of lacking chlorophyll, and their plastids do not differentiate into chloroplasts. [4]
Aneura mirabilis is a subterranean myco-heterotroph that obtains its nutrients from the abundant fungi growing among its tissues rather than from photosynthesis. The infecting fungus is a basidiomycete, a species of Tulasnella , which is also the case in fungi associated with other species of Aneura, [5] as well as the related genus Riccardia. However, this is not the case for other members of the Metzgeriales that have been studied. [3] Plants are white, lacking chlorophyll, and their plastids do not differentiate into chloroplasts. [4] They are small, seldom growing more than 3 cm (1.2 in) long. [6]
The species is dioicous, with individual plants producing either antheridia or archegonia, but never both. The female plants (with archegonia) are typically ten times the size of the male plants. [3] The development of reproductive structures is not controlled by photoperiod, but does require a temperature of at least 21 °C (70 °F) following a period of sufficiently low temperature. [7]
Aneura mirabilis was first reported by M. Denis in 1919, who considered it simply as a form of A. pinguis lacking chlorophyll. [5] In 1933, S. Malmborg placed it in a separate genus, Cryptothallus. Apart from lacking chlorophyll, it is very similar to species in the genus Aneura , and the validity of recognizing Cryptothallus as a separate genus was questioned by Karen Renzaglia in 1982, who suggested it may be considered "merely as an achlorophyllous species of Aneura." [8] A molecular phylogenetic study in 2008 placed the species firmly within Aneura, and it was transferred to that genus. [5] This decision was confirmed by a larger molecular phylogenetic study in 2010. [9]
It is suggested that the ancestor of Aneura mirabilis, like the related A. pinguis, had a mutualistic mycorrhizal association with Tulasnella, which was also able to form mycorrhizal connections with neighbouring trees. This evolved into a relationship where A. mirabilis gave up photosynthesis and obtained all its nutrients from the fungus, which in turn obtained them from the associated trees. Other evolutionary lineages of myco-heterotrophic plants have been shown to have evolved from photosynthetic, mycorrhizal ancestors. [5]
Initially, A. mirabilis was the only species of bryophyte known with the same combination of characteristics, [10] but in 1977 and 1979, a second species was collected in Costa Rica, and described in 1996 as Cryptothallus hirsutus (now Aneura crumii [1] ). [11] As of 2008 [update] , it had not been observed again. [5]
Plants have been found in locations across northern Europe, and once in Greenland. [3] They grow in bogs and are typically found underneath peat moss or other dense moss growth near birch trees. [6]
The Marchantiophyta are a division of non-vascular land plants commonly referred to as hepatics or liverworts. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of genetic information.
Hornworts are a group of non-vascular Embryophytes constituting the division Anthocerotophyta. The common name refers to the elongated horn-like structure, which is the sporophyte. As in mosses and liverworts, hornworts have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of genetic information; the flattened, green plant body of a hornwort is the gametophyte stage of the plant.
Marchantiales is an order of thallose liverworts that includes species like Marchantia polymorpha, a widespread plant often found beside rivers, and Lunularia cruciata, a common and often troublesome weed in moist, temperate gardens and greenhouses.
Lunularia cruciata, the crescent-cup liverwort, is a liverwort of the order Marchantiales, and the only species in the genus Lunularia and family Lunulariaceae. The name, from Latin luna, moon, refers to the moon-shaped gemma cups.
Metzgeriales is an order of liverworts. The group is sometimes called the simple thalloid liverworts: "thalloid" because the members lack structures resembling stems or leaves, and "simple" because their tissues are thin and relatively undifferentiated. All species in the order have a small gametophyte stage and a smaller, relatively short-lived, spore-bearing stage. Although these plants are almost entirely restricted to regions with high humidity or readily available moisture, the group as a whole is widely distributed, and occurs on every continent except Antarctica.
Takakia is a genus of two species of mosses known from western North America and central and eastern Asia. The genus is placed as a separate family, order and class among the mosses. It has had a history of uncertain placement, but the discovery of sporophytes clearly of the moss-type firmly supports placement with the mosses.
Conocephalum is a genus of complex thalloid liverworts in the order Marchantiales and is the only extant genus in the family Conocephalaceae. Some species of Conocephalum are assigned to the Conocephalum conicum complex, which includes several cryptic species. Conocephalum species are large liverworts with distinct patterns on the upper thallus, giving the appearance of snakeskin. The species Conocephalum conicum is named for its cone-shaped reproductive structures, called archegoniophores. Common names include snakeskin liverwort, great scented liverwort and cat-tongue liverwort.
Jungermanniopsida is the largest of three classes within the division Marchantiophyta (liverworts).
Buxbaumia is a genus of twelve species of moss (Bryophyta). It was first named in 1742 by Albrecht von Haller and later brought into modern botanical nomenclature in 1801 by Johann Hedwig to commemorate Johann Christian Buxbaum, a German physician and botanist who discovered the moss in 1712 at the mouth of the Volga River. The moss is microscopic for most of its existence, and plants are noticeable only after they begin to produce their reproductive structures. The asymmetrical spore capsule has a distinctive shape and structure, some features of which appear to be transitional from those in primitive mosses to most modern mosses.
Myco-heterotrophy is a symbiotic relationship between certain kinds of plants and fungi, in which the plant gets all or part of its food from parasitism upon fungi rather than from photosynthesis. A myco-heterotroph is the parasitic plant partner in this relationship. Myco-heterotrophy is considered a kind of cheating relationship and myco-heterotrophs are sometimes informally referred to as "mycorrhizal cheaters". This relationship is sometimes referred to as mycotrophy, though this term is also used for plants that engage in mutualistic mycorrhizal relationships.
Bryology is the branch of botany concerned with the scientific study of bryophytes. Bryologists are people who have an active interest in observing, recording, classifying or researching bryophytes. The field is often studied along with lichenology due to the similar appearance and ecological niche of the two organisms, even though bryophytes and lichens are not classified in the same kingdom.
Aneuraceae is a family of thallose liverworts in the order Metzgeriales. Most species are very small with narrow, branching thalli.
Treubiaceae is a family of liverworts in the order Treubiales. Species are large and leafy, and were previously classified among the Metzgeriales.
Haplomitriopsida is a newly recognized class of liverworts comprising fifteen species in three genera. Recent cladistic analyses of nuclear, mitochondrial, and plastid gene sequences place this monophyletic group as the basal sister group to all other liverworts. The group thus provides a unique insight into the early evolution of liverworts in particular and of land plants in general.
Blasiales is an order of liverworts with a single living family and two species. The order has traditionally been classified among the Metzgeriales, but molecular cladistics suggests a placement at the base of the Marchantiopsida.
Cryptothallus is a previously recognized genus of liverworts in the family Aneuraceae. The plants are small, and are white to pale green as a result of lacking chlorophyll. This feature led to the creation of a separate genus. The morphology of species assigned to Cryptothallus is very similar to that of Aneura. As a result, Karen Renzaglia in 1982 suggested that the only species then placed in the genus, Cryptothallus mirabilis, may be considered "merely as an achlorophyllous species of Aneura." Wickett and Goffinet argued the same position on the basis of sequences of nuclear, mitochondrial, and plastid DNA, and moved Cryptothallus mirabilis to Aneura. A 2010 molecular phylogenetic study confirmed the position of Cryptothallus within Aneura. This was accepted in the 2016 world checklist of hornworts and liverworts.
Riella is a genus in the liverwort family Riellaceae, and includes about eighteen species. Plants in the genus are small and grow submerged in shallow temporary pools. Although the genus is widely distributed in the Northern Hemisphere, locating populations is often difficult. Its occurrence is sporadic and local, and the tiny plants are ephemeral. The ornamented spores remain viable for several years, allowing the plants to survive annual drying of their habitat. The plants are easily grown in laboratory cultures.
Petalophyllum, or petalwort, is a genus of liverworts in the order Fossombroniales.
Aneura is a genus of liverworts in the family Aneuraceae.
Monoclea forsteri is one of the two species in the thallose liverwort family Monocleaceae. It is dioicous with the capsule dehiscing with a single longitudinal slit. Endemic and widely distributed throughout New Zealand, it is also the country's largest thalloid liverwort. Hooker described the species in 1820. The holotype is in the British Museum.