The Hysteriaceae (also known as Dothideomycetes, Ascomycotina, Eumycota) are a taxonomic
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 ...
of
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 ...
and the only
extant
Extant is the opposite of the word extinct. It may refer to:
* Extant hereditary titles
* Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English
* Extant taxon, a taxon which is not extinct, ...
family of the
order
Order, ORDER or Orders may refer to:
* Categorization, the process in which ideas and objects are recognized, differentiated, and understood
* Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...
Hysteriales
The Hysteriales are an order (biology), order of fungi in the class Dothideomycetes, subclass Pleosporomycetidae. It consists of a single family (biology), family, Hysteriaceae. Members of Hysteriales produce elongated, often boat shaped sexual s ...
. Members of the Hysteriaceae are defined by the possession of a
sexual structure called the hysterothecium, an elongated structure that opens by a longitudinal slit and releases sexually produced
spore
In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...
s. The family is widely distributed, with many species found in
temperate
In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...
regions,
and most are
saprobic on wood and bark, although a few are
parasitic on plants.
Description
The defining feature of this group—the hysterothecium—is a dense, persistent darkly colored structure, with a
boat-like shape and a pronounced lengthwise slit. Hysterothecia are capable of opening partially to reveal a
lenticular
Lenticular is an adjective often relating to lenses. It may refer to:
* A term used with two meanings in botany: see
* Lenticular cloud, a lens-shaped cloud
* Lenticular galaxy, a lens-shaped galaxy
* Lenticular (geology), adjective describing a ...
(lens-shaped), disk-like
hymenium
The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in others some ...
or closing tightly in response to
relative humidity
Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present.
Humidity depe ...
. They can be embedded in the
substratum
In linguistics, a stratum (Latin for "layer") or strate is a language that influences or is influenced by another through contact. A substratum or substrate is a language that has lower power or prestige than another, while a superstratum or sup ...
, bursting through the surface of the substratum (
erumpent), or rest entirely on the surface. They can be solitary or in groups,
ellipsoid
An ellipsoid is a surface that may be obtained from a sphere by deforming it by means of directional scalings, or more generally, of an affine transformation.
An ellipsoid is a quadric surface; that is, a surface that may be defined as the ...
to greatly elongated, and are sometimes branched, triradiate or borne on a crust- or net-like growth of
mycelium
Mycelium (plural mycelia) is a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. Fungal colonies composed of mycelium are found in and on soil and many other substrate (biology), substrates. A typical single ...
(a subiculum).
[Zogg H. (1962). Die Hysteriaceae ''s. str''. und Lophiaceae. ''Beitr Kryptogamenfl Schweiz'' 11: 1–190.] In vertical section, hysterothecia are globose to inversely ovoid (obovoid), with a thick three-layered
peridium, composed of small pseudo
parenchyma
Parenchyma () is the bulk of functional substance in an animal organ or structure such as a tumour. In zoology it is the name for the tissue that fills the interior of flatworms.
Etymology
The term ''parenchyma'' is New Latin from the word π ...
tous cells, the outer layer heavily encrusted with
pigment
A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compo ...
and often longitudinally
striated in age, the middle layer lighter in pigmentation and the inner layer distinctly thin-walled,
pallid and compressed.
[Barr ME. (1987). Prodromus to class Loculoascomycetes. Hamilton I. Newell, Inc., Amherst, Massachusetts: M.E. Barr Bigelow. 168 p.]
The hamathecium (hyphae or other tissues between
asci ASCI or Asci may refer to:
* Advertising Standards Council of India
* Asci, the plural of ascus, in fungal anatomy
* Accelerated Strategic Computing Initiative
* American Society for Clinical Investigation
* Argus Sour Crude Index
* Association of ...
) is composed of persistent cellular