The Hysteriaceae are a taxonomic
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 ...
and the only
extant
Extant or Least-concern species, least concern 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
* Exta ...
family of the
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
...
Hysteriales
The Hysteriales are an order of fungi in the class Dothideomycetes, subclass Pleosporomycetidae. It consists of a single family
Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Af ...
. 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 reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores fo ...
s. The family is widely distributed, with many species found in
temperate
In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...
regions,
and most are
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 ...
on wood and bark, although a few are
parasitic
Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The ent ...
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 Lens (optics), 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 de ...
(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 oth ...
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 (meteorology), precipitation, dew, or fog t ...
. They can be embedded in the
substratum
Substrata, plural of substratum, may refer to:
*Earth's substrata, the geologic layering of the Earth
*''Hypokeimenon'', sometimes translated as ''substratum'', a concept in metaphysics
*Substrata (album), a 1997 ambient music album by Biosphere
* ...
, bursting through the surface of the substratum (