''Aneura mirabilis'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

liverworts 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 ge ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Aneuraceae Aneuraceae (sometimes Riccardiaceae) is a family (biology), family of thallose Marchantiophyta, liverworts in the Order (biology), order Metzgeriales. Most species are very small with narrow, branching thalli. Taxonomy Aneuraceae is the largest ...

. It was first described in 1933, as ''Cryptothallus mirabilis''. Plants of this species are white as a result of lacking

chlorophyll Chlorophyll (also chlorophyl) is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words , ("pale green") and , ("leaf"). Chlorophyll allow plants to a ...

, and their

plastid The plastid (Greek: πλαστός; plastós: formed, molded – plural plastids) is a membrane-bound organelle found in the Cell (biology), cells of plants, algae, and some other eukaryotic organisms. They are considered to be intracellular endosy ...

s do not differentiate into

chloroplast A chloroplast () is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, and stores it in ...

Description

''Aneura mirabilis'' is a subterranean

myco-heterotroph Myco-heterotrophy (from Ancient Greek, Greek μύκης , "fungus", ἕτερος ', "another", "different" and τροφή ', "nutrition") is a symbiosis, symbiotic relationship between certain kinds of plants and fungi, in which the plant gets a ...

that obtains its nutrients from the abundant

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...

growing among its tissues rather than from

photosynthesis Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...

. The infecting fungus is a

basidiomycete Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Basi ...

, a species of ''

Tulasnella ''Tulasnella'' is a genus of effused (patch-forming) fungi in the order Cantharellales. Basidiocarps (fruit bodies), when visible, are typically smooth, ceraceous (waxy) to subgelatinous, frequently lilaceous to violet-grey, and formed on the un ...

'', which is also the case in fungi associated with other species of ''Aneura'', as well as the related genus ''Riccardia''. However, this is not the case for other members of the

Metzgeriales Metzgeriales is an Order (biology), order of Marchantiophyta, liverworts. The group is sometimes called the simple thalloid liverworts: "thallus, thalloid" because the members lack structures resembling stems or leaves, and "simple" because thei ...

that have been studied. Plants are white, lacking

, and their

s do not differentiate into

s. They are small, seldom growing more than long. The species is

dioicous Dioicy () is a sexual system where archegonia and antheridia are produced on separate gametophytes. It is one of the two main sexual systems in bryophytes. Both dioicous () and monoicous gametophytes produce gametes in gametangia by mitosis rathe ...

, with individual plants producing either

antheridia An antheridium is a haploid structure or organ producing and containing male gametes (called ''antherozoids'' or sperm). The plural form is antheridia, and a structure containing one or more antheridia is called an androecium. Androecium is also t ...

archegonia An archegonium (pl: archegonia), from the ancient Greek ''ἀρχή'' ("beginning") and ''γόνος'' ("offspring"), is a multicellular structure or organ of the gametophyte phase of certain plants, producing and containing the ovum or female ga ...

, but never both. The female plants (with archegonia) are typically ten times the size of the male plants. The development of reproductive structures is not controlled by

photoperiod Photoperiodism is the physiological reaction of organisms to the length of night or a dark period. It occurs in plants and animals. Plant photoperiodism can also be defined as the developmental responses of plants to the relative lengths of light a ...

, but does require a temperature of at least following a period of sufficiently low temperature.

Taxonomy

''Aneura mirabilis'' was first reported by M. Denis in 1919, who considered it simply as a form of '' A. pinguis'' lacking chlorophyll. 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''." A

molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

study in 2008 placed the species firmly within ''Aneura'', and it was transferred to that genus. This decision was confirmed by a larger molecular phylogenetic study in 2010. It is suggested that the ancestor of ''Aneura mirabilis'', like the related ''A. pinguis'', had a mutualistic

mycorrhizal A mycorrhiza (from Greek μύκης ', "fungus", and ῥίζα ', "root"; pl. mycorrhizae, mycorrhiza or mycorrhizas) is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plan ...

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. Initially, ''A. mirabilis'' was the only species of

bryophyte The Bryophyta s.l. are a proposed taxonomic division containing three groups of non-vascular land plants (embryophytes): the liverworts, hornworts and mosses. Bryophyta s.s. consists of the mosses only. They are characteristically limited in ...

known with the same combination of characteristics, but in 1977 and 1979, a second species was collected in Costa Rica, and described in 1996 as ''Cryptothallus hirsutus'' (now ''

Aneura crumii ''Aneura'' may refer to: * ''Aneura'' (fly), a genus of insects in the family Mycetophilidae * ''Aneura'' (plant), a genus of liverworts in the family Aneuraceae {{genus disambiguation ...

''). , it had not been observed again.

Distribution and habitat

Plants have been found in locations across northern

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

, and once in

Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is t ...

. They grow in bogs and are typically found underneath

peat moss ''Sphagnum'' is a genus of approximately 380 accepted species of mosses, commonly known as sphagnum moss, peat moss, also bog moss and quacker moss (although that term is also sometimes used for peat). Accumulations of ''Sphagnum'' can store wa ...

or other dense moss growth near

birch A birch is a thin-leaved deciduous hardwood tree of the genus ''Betula'' (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech-oak family Fagaceae. The genus ''Betula'' contains 30 ...

trees.

References

External links

Huldremossa ''Aneura mirabilis'' (''Cryptothallus mirabilis'')
a short article (in Swedish) with color photographs {{Taxonbar, from1=Q17464675, from2=Q3742941 Metzgeriales Parasitic plants Flora of Europe Flora of Greenland Plants described in 1933