Cryptothallus mirabilis
Encyclopedia
Cryptothallus mirabilis is a species
of liverworts
in the family
Aneuraceae
, and was first described in 1933. Plants of this species are white as a result of lacking chlorophyll
, and their plastid
s do not differentiate into chloroplast
s. Apart from lacking chlorophyll, Cryptothallus is very similar to the genus Aneura, and the validity of recognizing Cryptothallus as a separate genus has been questioned by Renzaglia, who suggests it may be considered "merely as an achlorophyllous species of Aneura."
Cryptothallus mirabilis is a subterranean myco-heterotroph
that obtains its nutrients from the abundant fungi
growing among its tissues rather than from photosynthesis
. Until recently, it was the only species of bryophyte
known with this combination of characteristics, but a second species Cryptothallus hirsutus was discovered in Costa Rica in 1996. The infecting fungus is a basidiomycete, which is also the case in fungi associated with the related genera Aneura and Riccardia. However, this is not the case for other members of the Metzgeriales
that have been studied.
The plants are small, seldom growing more than three centimeters long. They grow in bogs and are typically found underneath peat moss
or other dense moss growth near birch
trees. Plants have been found in locations across northern Europe
, and once in Greenland
.
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. The development of reproductive structures in Cryptothallus is not controlled by photoperiod
, but does require a temperature of at least 21 °C (69.8 °F) following a period of sufficiently low temperature.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of liverworts
Marchantiophyta
The Marchantiophyta are a division of bryophyte plants commonly referred to as hepatics or liverworts. Like other bryophytes, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of genetic information....
in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Aneuraceae
Aneuraceae
Aneuraceae is a family of thallose liverworts in the order Metzgeriales. Most species are very small with narrow, branching thalli....
, and was first described in 1933. Plants of this species are white as a result of lacking chlorophyll
Chlorophyll
Chlorophyll is a green pigment found in almost all plants, algae, and cyanobacteria. Its name is derived from the Greek words χλωρος, chloros and φύλλον, phyllon . Chlorophyll is an extremely important biomolecule, critical in photosynthesis, which allows plants to obtain energy from light...
, and their plastid
Plastid
Plastids are major organelles found in the cells of plants and algae. Plastids are the site of manufacture and storage of important chemical compounds used by the cell...
s do not differentiate into chloroplast
Chloroplast
Chloroplasts are organelles found in plant cells and other eukaryotic organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of processes called photosynthesis.Chloroplasts are green...
s. Apart from lacking chlorophyll, Cryptothallus is very similar to the genus Aneura, and the validity of recognizing Cryptothallus as a separate genus has been questioned by Renzaglia, who suggests it may be considered "merely as an achlorophyllous species of Aneura."
Cryptothallus mirabilis is a subterranean myco-heterotroph
Myco-heterotrophy
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...
that obtains its nutrients from the abundant fungi
Fungus
A fungus is a member of a large 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, Fungi, which is separate from plants, animals, and bacteria...
growing among its tissues rather than from photosynthesis
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...
. Until recently, it was the only species of bryophyte
Bryophyte
Bryophyte is a traditional name used to refer to all embryophytes that do not have true vascular tissue and are therefore called 'non-vascular plants'. Some bryophytes do have specialized tissues for the transport of water; however since these do not contain lignin, they are not considered to be...
known with this combination of characteristics, but a second species Cryptothallus hirsutus was discovered in Costa Rica in 1996. The infecting fungus is a basidiomycete, which is also the case in fungi associated with the related genera Aneura and Riccardia. However, this is not the case for other members of the Metzgeriales
Metzgeriales
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...
that have been studied.
The plants are small, seldom growing more than three centimeters long. They grow in bogs and are typically found underneath peat moss
Sphagnum
Sphagnum is a genus of between 151 and 350 species of mosses commonly called peat moss, due to its prevalence in peat bogs and mires. A distinction is made between sphagnum moss, the live moss growing on top of a peat bog on one hand, and sphagnum peat moss or sphagnum peat on the other, the...
or other dense moss growth near birch
Birch
Birch is a tree or shrub of the genus Betula , in the family Betulaceae, closely related to the beech/oak family, Fagaceae. The Betula genus contains 30–60 known taxa...
trees. Plants have been found in locations across northern Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, and once in Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...
.
The species is dioicous
Monoicous
Monoicous is a botanical term used to describe plants which bear both sperm and eggs on the same gametophyte. Dioicous is the complementary term describing species in which gametophytes produce only sperm or eggs but never both. The terms are used largely but not exclusively in the context of...
, with individual plants producing either antheridia
Antheridium
An antheridium or antherida is a haploid structure or organ producing and containing male gametes . It is present in the gametophyte phase of lower plants like mosses and ferns, and also in the primitive vascular psilotophytes...
or archegonia
Archegonium
An archegonium , from the ancient Greek ἀρχή and γόνος , is a multicellular structure or organ of the gametophyte phase of certain plants, producing and containing the ovum or female gamete. The archegonium has a long neck canal and a swollen base...
, but never both. The female plants (with archegonia) are typically ten times the size of the male plants. The development of reproductive structures in Cryptothallus is not controlled by photoperiod
Photoperiodism
Photoperiodism is the physiological reaction of organisms to the length of day or night. It occurs in plants and animals.Photoperiodism can also be defined as the developmental responses of plants to the relative lengths of the light and dark periods...
, but does require a temperature of at least 21 °C (69.8 °F) following a period of sufficiently low temperature.
External links
- Huldremossa Aneura mirabilis (Cryptothallus mirabilis), a short article (in Swedish) with color photographs