family
Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
of
fungi
A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...
in the
Ascomycota
Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The def ...
, class
Leotiomycetes
The Leotiomycetes are a class of ascomycete fungi. Many of them cause serious plant diseases.
Systematics
The class Leotiomycetes contains numerous species with an anamorph placed within the '' fungi imperfecti'' (deuteromycota), that have onl ...
. This is a
monotypic
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...
taxon, containing the single
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
''Loramyces''; the genus contains two aquatic species, ''L. juncicola'', named by American mycologist William H. Weston in 1929, and ''L. macrosporus'', first described by C.T. Ingold and B. Chapman in 1952.
Taxonomy
In his 1929 publication, Weston never designated an
order
Order, ORDER or Orders may refer to:
* A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica
* Categorization, the process in which ideas and objects are recognized, differentiated, and understood
...
or family for the genus ''Loramyces'', mentioning difficulties resolving its
taxonomic
280px, Generalized scheme of taxonomy
Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme of classes (a taxonomy) and the allocation ...
placement. The genus has been placed historically in several different families in the outdated Sphaeriales order, including the
Halosphaeriaceae
The Halosphaeriaceae are a family of fungi in the Sordariomycetes class, subclass Hypocreomycetidae. Halosphaeriaceae is the family with the largest number of marine fungi with a few species are from freshwater and terrestrial habitats (Jones et ...
, the Sphaeriaceae, the Loramycetaceae, and the
Trichosphaeriaceae
The Trichosphaeriales are an order of sac fungi. It is monotypic, and consists of the single family, the Trichosphaeriaceae. In 2017, the family of ''Trichosphaeriaceae'' was placed in Diaporthomycetidae families incertae sedis, which was accept ...
. The taxonomy of the genus was reevaluated in 1987, and was named by S. Digby and R.D. Goos in 1987. Species in the family are found in North America and Europe, where they grow in a
saprobic
Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed (dead or waste) organic matter. It occurs in saprotrophs, and is most often associated with fungi ...
fashion on submerged, decaying plant tissue.
Description
Members of the family Loramycetaceae lack stromata, the compact mass of
mycelium
Mycelium (: mycelia) is a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. Its normal form is that of branched, slender, entangled, anastomosing, hyaline threads. Fungal colonies composed of mycelium are fo ...
(with or without host tissue) that supports fruit bodies or in which fruiting bodies are produced. The
ascomata
An ascocarp, or ascoma (: ascomata), is the fruiting body (sporocarp (fungi), sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded ascus, asci, each of which typically contains four to ...
, which are formed within a gelatinous matrix, are deeply cup-shaped, almost like a
perithecium
An ascocarp, or ascoma (: ascomata), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. Ascoc ...
. The outer tissue layer of the ascomata is thin-walled and
translucent
In the field of optics, transparency (also called pellucidity or diaphaneity) is the physical property of allowing light to pass through the material without appreciable light scattering by particles, scattering of light. On a macroscopic scale ...
. The
ascospore
In fungi, an ascospore is the sexual spore formed inside an ascus—the sac-like cell that defines the division Ascomycota, the largest and most diverse Division (botany), division of fungi. After two parental cell nucleus, nuclei fuse, the ascu ...
s are 2-septate, translucent, and have a long basal cellular appendage with a gelatinous sheath. This sheath is thought to play the role of a "flotation mechanism", and ultimately give the ascospores a greater chance to become attached to the upper part of the host plant.
The black ascomata of ''Loramyces juncicola'' reach diameters of roughly 1.5–2 mm; they are shaped like flattened spheres when mature. Atop the ascomata are openings (
ostiole
An ''ostiole'' is a small hole or opening through which algae or fungi release their mature spores.
The word is a diminutive of wikt:ostium, "ostium", "opening".
The term is also used in higher plants, for example to denote the opening of the ...
s) that are 20–30
μm
The micrometre (Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a unit of length in the International System ...
wide and that protrude from the surface. After the ascomata have released their grey-colored ascospores, the top portion typically disintegrates leaving a partially closed cup. The spores of this species are
hyaline
A hyaline substance is one with a glassy appearance. The word is derived from , and .
Histopathology
Hyaline cartilage is named after its glassy appearance on fresh gross pathology. On light microscopy of H&E stained slides, the extracellula ...
, thin-walled, and spindle-shaped with dimensions of 17–22 μm long and 4–6 μm wide. The ascospores, which are surrounded by a gelatinous matrix, are divided into two cells by a
septa
SEPTA, the Southeastern Pennsylvania Transportation Authority, is a regional public transportation authority that operates bus, rapid transit, commuter rail, light rail, and electric trolleybus services for nearly four million people througho ...
. The
apical
Apical means "pertaining to an apex". It may refer to:
*Apical ancestor, refers to the last common ancestor of an entire group, such as a species (biology) or a clan (anthropology)
*Apical (anatomy), an anatomical term of location for features loc ...
cell has a bluntly rounded point, while the basal cell is thin and thread-like, bearing a slightly curved tail-like appendage.
Habitat
The species ''Loramyces juncicola'' was originally found on growing dead, partly softened stems of ''
Juncus militaris
''Juncus militaris'', the bayonet rush, is a species of flowering plant in the family Juncaceae
Juncaceae is a family of flowering plants, commonly known as the rush family. It consists of 8 genera and about 464 known species of slow-growin ...
'' that were submerged in fresh water to a depth of a few inches to as much as a few feet in a pond on
Nashawena Island
Nashawena Island is the second largest of the Elizabeth Islands of Dukes County, Massachusetts, United States. It lies between Cuttyhunk Island to the west and Pasque Island to the east. The island has a land area of and a population of 2 ...
, off the
Massachusetts
Massachusetts ( ; ), officially the Commonwealth of Massachusetts, is a U.S. state, state in the New England region of the Northeastern United States. It borders the Atlantic Ocean and the Gulf of Maine to its east, Connecticut and Rhode ...
coast. The habitat, situated a short distance inland, was buffered from the motion of waves by a thick growth of the ''Juncus'' plants that also partially shaded the water. It is known that warmer water inhibits the growth of ascomata, but it is not clear whether this is due to inhibition of the ''Loramyces'' fungus, or growth enhancement of bacteria that compete for nutrients. The gel-like substance surrounded the fruit bodies probably helps prevent the fungus from drying out when exposed to air by sinking water levels.