View source for Cyathus

{{short description|Genus of fungi in the Nidulariaceae}}
{{distinguish|Cyathium|Cyathea}}
{{featured article}}
<noinclude>{{pp-move|small=yes}}</noinclude>

{{stack begin}}
{{automatic taxobox
| image = 2012-10-22 Cyathus striatus (Huds.) Willd 274333 crop.jpg
| image_caption = ''Cyathus striatus''
| taxon = Cyathus
| authority = [[Albrecht von Haller|Haller]] (1768)
| type_species = ''[[Cyathus striatus]]''
| type_species_authority = ([[William Hudson (botanist)|Huds.]]) [[Carl Ludwig Willdenow|Willd.]] (1787)
| subdivision_ranks = [[Species]]
| subdivision = {{center|Approximately 100<ref>{{cite web|access-date=2024-12-26 |title=Cyathus |url=https://www.catalogueoflife.org/data/taxon/3XS7 |website=Catalogue of life}}<!-- auto-translated from Portuguese by Module:CS1 translator --></ref>}}
}}
{{mycomorphbox
| name = ''Cyathus''
| hymeniumType = gleba
| capShape = infundibuliform
| whichGills = NA
| stipeCharacter = NA
| ecologicalType = saprotrophic
| howEdible = inedible
}}
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'''''Cyathus''''' is a [[genus]] of [[fungi]] in the [[Nidulariaceae]], which is a [[family (biology)|family]] collectively known as the '''bird's nest fungi'''. They are given this name as they resemble tiny bird's nests filled with "eggs"{{snd}}structures large enough to have been mistaken in the past for seeds. However, these are now known to be reproductive structures containing [[spore]]s. The "eggs", or ''peridioles'', are firmly attached to the inner surface of this [[basidiocarp|fruit body]] by an elastic cord of [[mycelia]] known as a funiculus. The [[List of Cyathus species|45 species]] are widely distributed throughout the world and some are found in most countries, although a few exist in only one or two locales. ''[[Cyathus stercoreus]]'' is considered [[endangered]] in a number of European countries. Some species of ''Cyathus'' are also known as '''splash cups''', which refers to the fact that falling raindrops can knock the peridioles out of the open-cup fruit body. The internal and external surfaces of this cup may be ridged longitudinally (referred to as [[wikt:plication|plicate]] or [[wikt:striate|striate]]); this is one example of a [[Taxonomy (biology)|taxonomic]] characteristic that has traditionally served to distinguish between species.

Generally considered inedible, ''Cyathus'' species are [[saprobic]], since they obtain nutrients from decomposing [[organic matter]]. They usually grow on decaying wood or woody debris, on cow and horse dung, or directly on [[humus]]-rich soil. The [[biological life cycle|life cycle]] of this genus allows it to reproduce both sexually, with [[meiosis]], and asexually via spores. Several ''Cyathus'' species produce [[Natural product|bioactive]] compounds, some with medicinal properties, and several [[lignin]]-degrading [[enzyme]]s from the genus may be useful in [[bioremediation]] and [[agriculture]]. [[Phylogenetic]] analysis is providing new insights into the [[evolution]]ary relationships between the various species in ''Cyathus'', and has cast doubt on the validity of the older [[biological classification|classification]] systems that are based on traditional taxonomic characteristics.

==Taxonomy==

=== History ===
Bird's nest fungi were first mentioned by Flemish botanist [[Carolus Clusius]] in {{lang|la|Rariorum plantarum historia}} (1601). Over the next couple of centuries, these fungi were the subject of some controversy regarding whether the peridioles were seeds, and the mechanism by which they were dispersed in nature. For example, the French botanist [[Jean-Jacques Paulet]], in his work {{lang|fr|Traité des champignons}} (1790–1793), proposed the erroneous notion that peridioles were ejected from the fruit bodies by some sort of spring mechanism.<ref name="Brodie15">Brodie (1975), p. 15.</ref> The genus was established in 1768 by the Swiss scientist [[Albrecht von Haller]]; the [[Genus#Generic name|generic name]] {{lang|la|Cyathus}} is [[Latin (language)|Latin]], but it was originally derived from the [[Ancient Greek]] word {{lang|grc|κύαθος}}, meaning 'cup'.<ref name="Brodie150" /> The structure and biology of the genus ''Cyathus'' was better known by the mid-19th century, starting with the appearance in 1842 of a paper by Carl Johann Friedrich Schmitz,<ref name="Schmitz1842" /> and two years later, a [[monograph]] by the brothers [[Louis René Tulasne|Louis René]] and [[Charles Tulasne]].<ref name="Tulasne1844" /> The work of the Tulasnes was thorough and accurate, and was highly regarded by later researchers.<ref name="Brodie15" /><ref name="White1902" /><ref name="Lloyd1906" /> Subsequently, monographs were written in 1902 by Violet S. White (on American species),<ref name="White1902" /> [[Curtis Gates Lloyd]] in 1906,<ref name="Lloyd1906" /> [[G. H. Cunningham|Gordon Herriot Cunningham]] in 1924 (on New Zealand species),<ref name="Cunningham1924" /> and [[Harold J Brodie|Harold J. Brodie]] in 1975.<ref>Brodie, ''The Bird's Nest Fungi''.</ref>

==== Infrageneric classification ====
The genus ''Cyathus'' was first subdivided into two infrageneric groups (i.e., grouping species below the rank of genus) by the Tulasne brothers; the "eucyathus" group had fruit bodies with inner surfaces folded into [[pleat]]s (plications), while the "olla" group lacked plications.<ref name="Tulasne1844" /> Later (1906), [[Curtis Gates Lloyd|Lloyd]] published a different concept of infrageneric grouping in ''Cyathus'', describing five groups, two in the eucyathus group and five in the olla group.<ref name="Lloyd1906" />

In the 1970s, Brodie, in his monograph on bird's nest fungi, separated the genus ''Cyathus'' into seven related groups based on a number of [[Taxonomy (biology)|taxonomic]] characteristics, including the presence or absence of plications, the structure of the peridioles, the color of the fruit bodies, and the nature of the hairs on the outer peridium:<ref>Brodie (1975) pp. 150–80.</ref>

*'''''Olla'' group:''' Species with a [[Trichome#Plant trichomes|tomentum]] having fine flattened-down hairs, and no plications.
** ''[[Cyathus olla|C.&nbsp;olla]]'', ''C.&nbsp;africanus'', ''C.&nbsp;badius'', ''C.&nbsp;canna'', ''C.&nbsp;colensoi'', ''C.&nbsp;confusus'', ''C.&nbsp;earlei'', ''C.&nbsp;hookeri'', ''C.&nbsp;microsporus'', ''C.&nbsp;minimus'', ''C.&nbsp;pygmaeus''
*'''''Pallidus'' group:''' Species with conspicuous, long, downward-pointing hairs, and a smooth (non-plicate) inner peridium.
** ''C.&nbsp;pallidus'', ''C.&nbsp;julietae''
*'''''Triplex'' group: '''Species with mostly dark-colored peridia, and a silvery white inner surface.
** ''C.&nbsp;triplex'', ''C.&nbsp;setosus'', ''C.&nbsp;sinensis''
*'''''Gracilis'' group:''' Species with tomentum hairs clumped into tufts or mounds.
** ''C.&nbsp;gracilis'', ''C.&nbsp;intermedius'', ''C.&nbsp;crassimurus'', ''C.&nbsp;elmeri''[[File:Cyathus striatus Uurrepesäsieni H7618 C.jpg|thumb|right|The shaggy (tomentose) outer peridial surface of ''[[Cyathus striatus|C.&nbsp;striatus]]'']]
*'''''Stercoreus'' group:''' Species with non-plicate peridia, shaggy or wooly outer peridium walls, and dark to black peridioles.
** ''C.&nbsp;stercoreus'', ''C.&nbsp;pictus'', ''C.&nbsp;fimicola''
*'''''Poeppigii'' group:''' Species with plicate internal peridial walls, hairy to shaggy outer walls, dark to black peridioles, and large, roughly spherical or ellipsoidal spores.
** ''C.&nbsp;poeppigii'', ''C.&nbsp;crispus'', ''C.&nbsp;limbatus'', ''[[Cyathus gayanus|C.&nbsp;gayanus]]'', ''C.&nbsp;costatus'', ''C.&nbsp;cheliensis'', ''C.&nbsp;olivaceo-brunneus''
*'''''Striatus'' group:''' Species with plicate internal peridia, hairy to shaggy outer peridia, and mostly elliptical spores.
** ''[[Cyathus striatus|C.&nbsp;striatus]]'', ''C.&nbsp;annulatus'', ''C.&nbsp;berkeleyanus'', ''C.&nbsp;bulleri'', ''C.&nbsp;chevalieri'', ''C.&nbsp;ellipsoideus'', ''[[Cyathus helenae|C.&nbsp;helenae]]'', ''C.&nbsp;montagnei'', ''C.&nbsp;nigro-albus'', ''C.&nbsp;novae-zeelandiae'', ''C.&nbsp;pullus'', ''C.&nbsp;rudis''

===Phylogeny===
The 2007 publication of [[phylogenetic]] analyses of [[DNA sequence]] data of numerous ''Cyathus'' species has cast doubt on the validity of the morphology-based infrageneric classifications described by Brodie. This research suggests that ''Cyathus'' species can be grouped into three genetically related [[clade]]s:<ref name="Zhao2007" />
[[File:Cyathus dominicanus.png|thumb|upright|''[[Cyathus dominicanus|C. dominicanus]]'', an extinct species|alt=]]

*'''''Ollum'' group:'''
**''C.&nbsp;africanus'' ([[type species|type]]), ''C.&nbsp;africanus'' [[Form (botany)|f.]] ''latisporus'', ''C.&nbsp;conlensoi'', ''C.&nbsp;griseocarpus'', ''C.&nbsp;guandishanensis'', ''C.&nbsp;hookeri'', ''C.&nbsp;jiayuguanensis'', ''[[Cyathus olla|C.&nbsp;olla]]'', ''C.&nbsp;olla'' f. ''anglicus'', and ''C.&nbsp;olla'' f. ''brodiensis''.
*'''''Striatum'' group:'''
**''C.&nbsp;annulatus'', ''C.&nbsp;crassimurus'', ''[[Cyathus helenae|C.&nbsp;helenae]]'', ''C.&nbsp;poeppigii'', ''C.&nbsp;renwei'', ''C.&nbsp;setosus'', ''[[Cyathus stercoreus|C.&nbsp;stercoreus]]'', and ''C.&nbsp;triplex''.
*'''''Pallidum'' group:'''
**''C.&nbsp;berkeleyanus'', ''C.&nbsp;olla'' f. ''lanatus'', ''C.&nbsp;gansuensis'', and ''C.&nbsp;pallidus''.

This analysis shows that rather than fruit body structure, [[spore]] size is generally a more reliable character for segregating species groups in ''Cyathus''.<ref name="Zhao2007" /> For example, species in the ''ollum'' clade all have spore lengths less than 15&nbsp;μm, while all members of the ''pallidum'' group have lengths greater than 15&nbsp;μm; the ''striatum'' group, however, cannot be distinguished from the ''pallidum'' group by spore size alone. Two characteristics are most suited for distinguishing members of the ''ollum'' group from the ''pallidum'' group: the thickness of the hair layer on the peridium surface, and the outline of the fruit bodies. The tomentum of ''Pallidum'' species is thick, like felt, and typically aggregates into clumps of shaggy or woolly hair. Their crucible-shaped fruit bodies do not have a clearly differentiated stipe. The exoperidium of ''Ollum'' species, in comparison, has a thin tomentum of fine hairs; fruit bodies are funnel-shaped and have either a constricted base or a distinct [[stipe (mycology)|stipe]].<ref name="Zhao2007" />

==Description==
Species in the genus ''Cyathus'' have fruit bodies ([[peridium|peridia]]) that are vase-, trumpet- or urn-shaped with dimensions of {{Convert|4–8|mm|abbr=off|frac=16}} wide by {{Convert|7–18|mm|abbr=on|frac=16}} tall.<ref name=Miller1988/> Fruit bodies are brown to gray-brown in color, and covered with small hair-like structures on the outer surface. Some species, like ''[[Cyathus striatus|C.&nbsp;striatus]]'' and ''C.&nbsp;setosus'', have conspicuous bristles called setae on the rim of the cup. The fruit body is often expanded at the base into a solid rounded mass of [[hypha]]e called an emplacement, which typically becomes tangled and entwined with small fragments of the underlying growing surface, improving its stability and helping it from being knocked over by rain.<ref>Brodie (1975), pp. 5–7.</ref>[[File:Cyathus striatus Buller.jpg|thumb|left|''Cyathus striatus'' (a) young and mature fruit bodies in longitudinal section; (b), (c) single peridiole entire, and in section]] Immature fruit bodies have a whitish membrane, an epiphragm, that covers the peridium opening when young, but eventually [[Dehiscence (botany)|dehisces]], breaking open during maturation. Viewed with a microscope, the peridium of ''Cyathus'' species is made of three distinct layers—the endo-, meso-, and ectoperidium, referring to the inner, middle, and outer layers respectively. While the surface of the ectoperidium in ''Cyathus'' is usually hairy, the endoperidial surface is smooth, and depending on the species, may have longitudinal grooves (striations).<ref name=Brodie150/>

Because the basic fruit body structure in all [[genus|genera]] of the family Nidulariaceae is essentially similar, ''Cyathus'' may be readily confused with species of ''[[Nidula]]'' or ''[[Crucibulum (fungus)|Crucibulum]]'', especially older, weathered specimens of ''Cyathus'' that may have the hairy ectoperidium worn off.<ref>Brodie (1975), p. 147.</ref> It distinguished from ''Nidula'' by the presence of a funiculus, a cord of hyphae attaching the peridiole to the endoperidium. ''Cyathus'' differs from genus ''Crucibulum'' by having a distinct three-layered wall and a more intricate funiculus.<ref name=Brodie150/>

===Peridiole structure===
[[File:Peridiole cross section.svg|thumb|right|A peridiole and attached funiculus in cross section
{{legend-col
|thumb size=wide
|a: [[Peridium|tunica]]
|b: [[spore]]s
|c: [[Basidium|basidia]]
|d: [[Purse (biology)|purse]]
|e: [[funicular cord]]
|f: [[hapteron]]
|g: [[middle piece]]
}}
]]
Derived from the Greek word ''peridion'', meaning "small leather pouch",<ref>Alexopolous ''et al.'' (1996), p. 545.</ref> the peridiole is the "egg" of the bird's nest. It is a mass of [[basidiospores]] and [[gleba]]l tissue enclosed by a hard and waxy outer shell. The shape may be described as lenticular—like a [[biconvex lens]]—and depending on the species, may range in color from whitish to grayish to black. The interior chamber of the peridiole contains a [[hymenium]] that is made of [[basidia]], sterile (non-reproductive) structures, and spores. In young, freshly opened fruit bodies, the peridioles lie in a clear gelatinous substance which soon dries.<ref>Brodie (1975), p. 6.</ref>

Peridioles are attached to the fruit body by a funiculus, a complex structure of hyphae that may be differentiated into three regions: the basal piece, which attaches it to the inner wall of the peridium, the middle piece, and an upper sheath, called the purse, connected to the lower surface of the peridiole. In the purse and middle piece is a coiled thread of interwoven hyphae called the funicular cord, attached at one end to the peridiole and at the other end to an entangled mass of hyphae called the hapteron. In some species the peridioles may be covered by a tunica, a thin white membrane (particularly evident in ''C.&nbsp;striatus'' and ''C.&nbsp;crassimurus'').<ref>Brodie (1975), p. 129.</ref>
Spores typically have an elliptical or roughly spherical shape, and are thick-walled, [[hyaline]] or light yellow-brown in color, with dimensions of 5–15 by 5–8&nbsp;[[micrometre|μm]].<ref name=Miller1988/>

=== Life cycle ===
The life cycle of the genus ''Cyathus'', which contains both [[haploid]] and [[diploid]] stages, is typical of [[taxa]] in the [[basidiomycetes]] that can reproduce both asexually (via [[vegetative reproduction|vegetative]] spores), or sexually (with [[meiosis]]). Like other wood-decay fungi, this life cycle may be considered as two functionally different phases: the vegetative stage for the spread of [[mycelia]], and the reproductive stage for the establishment of spore-producing structures, the fruit bodies.<ref name="Schmidt2006" />

The vegetative stage encompasses those phases of the life cycle involved with the germination, spread, and survival of the mycelium. Spores germinate under suitable conditions of moisture and temperature, and grow into branching filaments called hyphae, pushing out like roots into the rotting wood. These hyphae are [[homokaryotic]], containing a single [[nucleus (cell)|nucleus]] in each compartment; they increase in length by adding cell-wall material to a growing tip. As these tips expand and spread to produce new growing points, a network called the mycelium develops. Mycelial growth occurs by [[mitosis]] and the synthesis of hyphal biomass. When two homokaryotic hyphae of different [[mating type|mating compatibility groups]] fuse with one another, they form a [[dikaryon|dikaryotic]] mycelia in a process called [[plasmogamy]]. Prerequisites for mycelial survival and colonization a substrate (like rotting wood) include suitable humidity and nutrient availability. The majority of ''Cyathus'' species are [[saprobic]], so mycelial growth in rotting wood is made possible by the secretion of [[enzyme]]s that break down complex [[polysaccharide]]s (such as [[cellulose]] and [[lignin]]) into simple sugars that can be used as nutrients.<ref>Deacon (2005), pp. 231–4.</ref>

After a period of time and under the appropriate environmental conditions, the dikaryotic mycelia may enter the reproductive stage of the life cycle. Fruit body formation is influenced by external factors such as season (which affects temperature and air humidity), nutrients and light. As fruit bodies develop they produce peridioles containing the basidia upon which new basidiospores are made. Young basidia contain a pair of haploid sexually compatible nuclei which fuse, and the resulting diploid fusion nucleus undergoes meiosis to produce basidiospores, each containing a single haploid nucleus.<ref>Deacon (2005) pp. 31–2.</ref> The dikaryotic mycelia from which the fruit bodies are produced is long lasting, and will continue to produce successive generations of fruit bodies as long as the environmental conditions are favorable.

[[File:Cyathus stercoreus Fruchtkörper.JPG|thumb|''[[Cyathus stercoreus]]'']]
The development of ''Cyathus'' fruit bodies has been studied in laboratory culture; ''C.&nbsp;stercoreus'' has been used most often for these studies due to the ease with which it may be grown experimentally.<ref name="Brodie1948" /> In 1958, E. Garnett first demonstrated that the development and form of the fruit bodies is at least partially dependent on the intensity of light it receives during development. For example, exposure of the [[heterokaryotic]] mycelium to light is required for fruit to occur, and furthermore, this light needs to be at a [[wavelength]] of less than 530 [[nanometer|nm]]. Continuous light is not required for fruit body development; after the mycelium has reached a certain stage of maturity, only a brief exposure to light is necessary, and fruit bodies will form if even subsequently kept in the dark.<ref name="Garnett1958" /> Lu suggested in 1965 that certain growing conditions—such as a shortage in available nutrients—shifts the fungus' [[metabolism]] to produce a hypothetical "photoreceptive precursor" that enables the growth of the fruit bodies to be stimulated and affected by light.<ref name="Lu1965" /> The fungi is also positively [[phototropism|phototropic]], that is, it will orient its fruit bodies in the direction of the light source.<ref>Brodie (1975), pp. 57–8.</ref> The time required to develop fruit bodies depends on a number of factors, such as the temperature, or the availability and type of nutrients, but in general "most species that do fruit in laboratory culture do so best at about 25 °C, in from 18 to 40 days."<ref>Brodie (1975), p. 48.</ref>

=== Bioactive compounds ===
{{multiple image
| align             = right
| image1            = Cyathin A3.svg
| width1            = 110
| alt1              =
| caption1          =
| image2            = Cyathuscavin general structure.svg
| width2            = 120
| alt2              =
| caption2          =
| footer            = Structures of cyathin A<sub>3</sub> (left) and cyathuscavins (right)<ref>{{KEGG compound|C09079}}</ref><ref name=Kang2008/>
}}
A number of species of ''Cyathus'' produce [[metabolites]] with biological activity, and novel chemical structures that are specific to this genus. For example, [[cyathin]]s are [[diterpenoid]] compounds produced by ''[[Cyathus helenae|C.&nbsp;helenae]]'',<ref name="Allbutt1971" /><ref name="Ayer1972" /> ''C.&nbsp;africanus''<ref name="Ayer1978" /> and ''C.&nbsp;earlei''.<ref name="Ayer1979" /> Several of the cyathins (especially cyathins B<sub>3</sub> and C<sub>3</sub>), including [[striatin]] compounds from ''C.&nbsp;striatus'',<ref name="Anke1977" /> show strong [[antibiotic]] activity.<ref name="Allbutt1971" /><ref name="Johri1971" /> [[Cyathane]] diterpenoids also stimulate [[nerve growth factor]] synthesis, and have the potential to be developed into therapeutic agents for [[neurodegenerative disorder]]s such as [[Alzheimer's disease]].<ref name="Krzyczkowski12008" /> Compounds named [[cyathuscavin]]s, isolated from the mycelial [[liquid culture]] of ''C.&nbsp;stercoreus'', have significant [[antioxidant]] activity,<ref name="Kang2008" /> as do the compounds known as [[cyathusal]]s, also from ''C.&nbsp;stercoreus''.<ref name="Kang2007" /> Various [[sesquiterpene]] compounds have also been identified in ''C.&nbsp;bulleri'', including [[cybrodol]] (derived from [[humulene]]),<ref name="Ayer1981" /> [[nidulol]], and [[bullerone]].<ref name="Ayer1987" />

== Distribution and habitat ==
Fruit bodies typically grow in clusters, and are found on dead or decaying wood, or on woody fragments in cow or horse dung.<ref name="Miller1988" /> Dung-loving (coprophilous) species include ''[[Cyathus stercoreus|C.&nbsp;stercoreus]]'', ''C.&nbsp;costatus'', ''C.&nbsp;fimicola'', and ''C.&nbsp;pygmaeus''.<ref>Brodie (1975), pp. 102–3.</ref> Some species have been collected on woody material like dead [[herbaceous]] stems, the empty shells or [[husk]]s of nuts, or on fibrous material like [[coconut]], [[jute]], or [[hemp]] fiber woven into matting, sacks or cloth.<ref>Brodie (1975), p. 105.</ref> In nature, fruit bodies are usually found in moist, partly shaded sites, such as the edges of woods on trails, or around lighted openings in forests. They are less frequently found growing in dense vegetation and deep mosses, as these environments would interfere with the dispersal of peridioles by falling drops of water.<ref name="Brodie101">Brodie (1975), p. 101.</ref> The appearance of fruit bodies is largely dependent upon features of the immediate growing environment; specifically, optimum conditions of temperature, moisture, and nutrient availability are more important factors for fruit rather than the broad geographical area in which the fungi are located, or the season.<ref name="Brodie101" /> Examples of the ability of ''Cyathus'' to thrive in somewhat inhospitable environments are provided by ''C.&nbsp;striatus'' and ''C.&nbsp;stercoreus'', which can survive the drought and cold of winter in temperate North America,<ref name="Brodie1958" /> and the species ''[[Cyathus helenae|C.&nbsp;helenae]]'', which has been found growing on dead [[alpine plants]] at an altitude of {{convert|7000|ft|m|order=flip}}.<ref name="Brodie1966" />
[[File:Cyathus poeppigii.jpg|thumb|''C. poeppigii'', a tropical species]]
In general, species of ''Cyathus'' have a worldwide [[range (biology)|distribution]], but are only rarely found in the [[arctic]] and [[subarctic]].<ref name="Brodie150">Brodie (1975), p. 150.</ref> One of the best known species, ''C.&nbsp;striatus'' has a circumpolar distribution and is commonly found throughout [[temperate]] locations, while the morphologically similar ''C.&nbsp;poeppigii'' is widely spread in [[tropical]] areas, rarely in the [[subtropics]], and never in temperate regions.<ref>Brodie (1975), p. 116.</ref> The majority of species are native to warm climates. For example, although 20 different species have been reported from the United States and Canada, only 8 are commonly encountered; on the other hand, 25 species may be regularly found in the [[West Indies]], and the [[Hawaiian Islands]] alone have 11 species.<ref name="Brodie117">Brodie (1975), p. 117.</ref> Some species seem to be [[endemism|endemic]] to certain regions, such as ''C.&nbsp;novae-zeelandiae'' found in [[New Zealand]], or ''C.&nbsp;crassimurus'', found only in Hawaii; however, this apparent endemism may just be a result of a lack of collections, rather than a difference in the habitat that constitutes a barrier to spread.<ref name="Brodie117" /> Although widespread in the tropics and most of the temperate world, ''C.&nbsp;stercoreus'' is only rarely found in Europe; this has resulted in its appearance on a number of [[Red List of Endangered Species|Red Lists]]. For example, it is considered [[endangered]] in [[Bulgaria]],<ref name="Gyosheva2006" /> [[Denmark]],<ref name="urlDMU - B-FDC - Den danske Rødliste -" /> and [[Montenegro]],<ref name="urlwww.wsl.ch" /> and "near threatened" in [[Great Britain]].<ref name="urlwww.fieldmycology.net" /> The discovery of a ''Cyathus'' species in [[Dominican amber]] (''[[Cyathus dominicanus|C.&nbsp;dominicanus]]'') suggests that the basic form of the bird's nest fungi had already evolved by the [[Cretaceous]] era and that the group had diversified by the mid-[[Cenozoic]].<ref name="Poiner 2014" />

==Ecology==

=== Spore dispersal ===
Like other bird's nest fungi in the [[Nidulariaceae]], species of ''Cyathus'' have their spores dispersed when water falls into the fruit body. The fruit body is shaped so that the kinetic energy of a fallen raindrop is redirected upward and slightly outward by the angle of the cup wall, which is consistently 70–75° with the horizontal.<ref>Brodie (1975), p. 89.</ref> The action ejects the peridioles out of the so-called "splash cup", where it may break and spread the spores within, or be eaten and dispersed by animals after passing through the digestive tract. This method of spore dispersal in the Nidulariaceae was tested experimentally by George Willard Martin in 1924,<ref name="Martin1927" /> and later elaborated by Arthur Henry Reginald Buller, who used ''C.&nbsp;striatus'' as the model species to experimentally investigate the phenomenon.<ref name="Buller1942" /> Buller's major conclusions about spore dispersal were later summarized by his graduate student Harold J. Brodie, with whom he conducted several of these splash cup experiments: <blockquote>Raindrops cause the peridioles of the Nidulariaceae to be thrown about four feet by splash action. In the genus ''Cyathus'', as a peridiole is jerked out of its cup, the funiculus is torn and this makes possible the expansion of a mass of adhesive hyphae (the hapteron) which clings to any object in the line of flight. The momentum of the peridiole causes a long cord to be pulled out of a sheath attached to the peridiole. The peridiole is checked in flight and the jerk causes the funicular cord to become wound around stems or entangled among plant hairs. Thus the peridiole becomes attached to vegetation and may be eaten subsequently by herbivorous animals.<ref name="Brodie1951" /></blockquote>

Although it has not been shown experimentally if the spores can survive the passage through an animal's digestive tract, the regular presence of ''Cyathus'' on cow or horse manure strongly suggest that this is true.<ref>Alexopolous ''et al.'' (1996), p. 555.</ref> Alternatively, the hard outer casing of peridioles ejected from splash cups may simply disintegrate over time, eventually releasing the spores within.<ref name="Orr1979" />

==Uses==
Species in the family Nidulariaceae, including ''Cyathus'', are considered inedible, as (in Brodie's words) they are "not sufficiently large, fleshy, or odorous to be of interest to humans as food".<ref>Brodie (1975), p. 119.</ref> However, there have not been reports of poisonous [[alkaloid]]s or other substances considered toxic to humans. Brodie goes on to note that two ''Cyathus'' species have been used by native peoples as an [[aphrodisiac]], or to stimulate [[fertility]]: ''C.&nbsp;limbatus'' in [[Colombia]], and ''C.&nbsp;microsporus'' in [[Guadeloupe]]. Whether these species have any actual effect on [[human physiology]] is unknown.<ref>Brodie (1975), p. 120.</ref>

===Biodegradation===
[[File:Cyathus olla.jpg|thumb|''Cyathus olla''; note the smooth (not plicate) endoperidium, and relatively large peridioles.]]
[[Lignin]] is a complex polymeric chemical compound that is a major constituent of wood. Resistant to biological decomposition, its presence in paper makes it weaker and more liable to discolor when exposed to light. The species ''C.&nbsp;bulleri'' contains three lignin-degrading enzymes: [[lignin peroxidase]], [[manganese peroxidase]], and [[laccase]].<ref name=Vasdev1995/> These [[enzyme]]s have potential applications not only in the [[pulp and paper industry]], but also to increase the digestibility and protein content of [[forage]] for cattle. Because laccases can break down [[Phenols|phenolic compounds]] they may be used to detoxify some environmental pollutants, such as [[dye]]s used in the [[textile industry]].<ref name=Chabra2008/><ref name=Salony2008/><ref name=Salony2006/> ''C.&nbsp;bulleri'' laccase has also been [[Genetic engineering|genetically engineered]] to be produced by ''[[Escherichia coli]]'', making it the first fungal laccase to be produced in a bacterial host.<ref name=Salony2008/> ''C.&nbsp;pallidus'' can [[biodegrade]] the explosive compound [[RDX]] (hexahydro-1,3,5-trinitro-1,3,5-triazine), suggesting it might be used to decontaminate [[munition]]s-contaminated soils.<ref name=Bayman1995/>

===Agriculture===
''[[Cyathus olla]]'' has been investigated for its ability to accelerate the decomposition of stubble left in the field after harvest, effectively reducing [[plant pathology|pathogen]] populations and accelerating [[nutrient cycling]] through [[mineralization (soil)|mineralization]] of essential plant nutrients.<ref name=Blenis2005/><ref name=ShinnerCarnelly2002/>

=== Human biology ===
Various ''Cyathus'' species have antifungal activity against human pathogens such as ''[[Aspergillus fumigatus]]'', ''[[Candida albicans]]'' and ''[[Cryptococcus neoformans]]''.<ref name="Lui2004" /> Extracts of ''C.&nbsp;striatus'' have inhibitory effects on [[NF-κB]], a [[transcription factor]] responsible for [[Regulation of gene expression|regulating the expression]] of several genes involved in the [[immune system]], [[inflammation]], and [[Programmed cell death|cell death]].<ref name="Petrova2007" />

==References==
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<ref name=Kang2008>{{cite journal |vauthors=Kang HS, Kim KR, Jun EM, Park SH, Lee TS, Suh JW, Kim JP |title=Cyathuscavins A, B, and C, new free radical scavengers with DNA protection activity from the Basidiomycete ''Cyathus stercoreus'' |journal=Bioorganic & Medicinal Chemistry Letters |volume=18 |issue=14 |pages=4047–50 |year=2008 |pmid=18565749 |doi=10.1016/j.bmcl.2008.05.110 |url=https://zenodo.org/record/891111 |access-date=2019-07-04 |archive-date=2023-04-19 |archive-url=https://web.archive.org/web/20230419001151/https://zenodo.org/record/891111 |url-status=live }}</ref>

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<ref name=Kirk2008>{{cite book |vauthors=Kirk MP, Cannon PF, Minter DW, Stalpers JA |title=Dictionary of the Fungi |edition=10th |publisher=CAB International |location=Wallingford, UK |year=2008 |page=185 |isbn=978-0-85199-826-8}}</ref>
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<ref name=Krzyczkowski12008>{{cite journal |author=Krzyczkowski W. |title=The structure, medicinal properties and biosynthesis of cyathane diterpenoids |url=https://www.researchgate.net/publication/285875338 |journal=Biotechnologia |year=2008 |volume=1 |issue=80 |pages=146–67}}</ref>

<ref name=Lloyd1906>{{cite journal |author=Lloyd CG. |year=1906 |title=The Nidulariaceae |journal=Mycological Writings |volume=2 |pages=1–30}}</ref>

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<ref name=Salony2006>{{cite journal |vauthors=Salony, Mishra S, Bisaria VS |title=Production and characterization of laccase from ''Cyathus bulleri'' and its use in decolourization of recalcitrant textile dyes |journal=Applied Microbiology and Biotechnology |volume=71 |issue=5 |pages=646–53 |year=2006 |pmid=16261367 |doi=10.1007/s00253-005-0206-4|s2cid=38760041 }}</ref>

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<ref name=Schmitz1842>{{cite journal |author=Schmitz J. |year=1842 |language=de |title=Morphologische Beobachtungen als Beiträge zur Leben und Entwicklungsgeschichte einiger Schwämme aus der Klasse der Gastromyceten und Hymenomyceten |journal=Linnaea |volume=16 |pages=141–215 |url=https://archive.org/stream/linnaea16schl#page/n147/mode/2up}}</ref>

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<ref name="urlwww.fieldmycology.net">{{cite web |url=http://www.fieldmycology.net/Download/RDL_of_Threatened_British_Fungi.pdf |title=The Red Data List of threatened British fungi |author=Evans S. |publisher=British Mycological Society |year=2007 |access-date=2009-03-26 |archive-date=2010-12-14 |archive-url=https://web.archive.org/web/20101214091932/http://www.fieldmycology.net/Download/RDL_of_Threatened_British_Fungi.pdf |url-status=usurped }}</ref>

<ref name="urlwww.wsl.ch">{{cite web |url=http://www.wsl.ch/eccf/Montenegro05.pdf |vauthors=Peric B, Peric O |title=The provisory red list of endangered macromycetes of Montenegro |publisher=European Council for the Conservation of Fungi |year=2005 |access-date=2009-03-26 |archive-date=2016-03-03 |archive-url=https://web.archive.org/web/20160303205851/http://www.wsl.ch/eccf/Montenegro05.pdf |url-status=live }}</ref>

<ref name=Vasdev1995>{{cite thesis |author=Vasdev K. |title=Lignin degrading enzymes and ligninolytic system of ''Cyathus'' sp |year=1995 |degree=PhD |publisher=University of Delhi |location=Delhi, India}}</ref>

<ref name=White1902>{{cite journal |author=White VS. |year=1902 |title=The Nidulariaceae of North America |jstor=2478721 |journal=Bulletin of the Torrey Botanical Club |volume=29 |issue=5 |pages=251–80 |doi=10.2307/2478721}}</ref>

<ref name=Zhao2007>{{cite journal |vauthors=Zhao RL, Jeewon R, Desjardin DE, Soytong K, Hyde KD |title=Ribosomal DNA phylogenies of ''Cyathus'': is the current infrageneric classification appropriate? |journal=Mycologia |volume=99 |issue=3 |pages=385–95 |year=2007 |pmid=17883030 |doi=10.3852/mycologia.99.3.385}}</ref>

}}

==Cited texts==
* {{cite book |vauthors=Alexopoulos CJ, Mims CW, Blackwell M |title=Introductory Mycology |edition=4th |publisher=Wiley |location=New York, New York |year=1996 |isbn=0-471-52229-5}}
* {{cite book |author=Brodie HJ. |title=The Bird's Nest Fungi |publisher=University of Toronto Press |location=Toronto |year=1975 |isbn=0-8020-5307-6}}
* {{cite book |author=Deacon J. |title=Fungal Biology |publisher=Blackwell Publishers |location=Cambridge, Massachusetts |year=2005 |isbn=1-4051-3066-0}}

==External links==
{{Portal|Fungi}}
*{{Wikispecies-inline}}
* [http://www.svims.ca/council/Bird's.htm Trial field key to the species of BIRD'S NEST FUNGI in the Pacific Northwest]

{{Taxonbar|from=Q1580329}}

[[Category:Agaricales genera]]
[[Category:Nidulariaceae]]