# Cyathus striatus
**Cyathus striatus** (Huds.) Willd., commonly called the fluted bird's nest fungus, is a saprobic basidiomycete in the family [Nidulariaceae](https://www.edgepedia.org/nidulariaceae) whose small, hairy, cup-shaped fruiting bodies contain lens-shaped spore packets called peridioles and are lined inside with lengthwise grooves, or striations[1](https://www.first-nature.com/fungi/cyathus-striatus.php) • [2](https://myco-lb.jgi.doe.gov/Cyastr2/Cyastr2.home.html). It is widespread in temperate regions throughout the world and fruits on twigs, wood chips, old boards, and other woody debris of deciduous forests[2](https://myco-lb.jgi.doe.gov/Cyastr2/Cyastr2.home.html).
| Key fact | Detail |
|---|---|
| Scientific name | *Cyathus striatus* (Huds.) Willd.; originally described as *Peziza striata* by William Hudson in 1778, transferred to *Cyathus* by Christiaan Hendrik Persoon in 1801[1](https://www.first-nature.com/fungi/cyathus-striatus.php) |
| Fruitbody size | Peridia 6 to 10 mm across and 6 to 15 mm tall, funnel-shaped, tapering outward toward the rim[1](https://www.first-nature.com/fungi/cyathus-striatus.php) |
| Diagnostic features | Shaggy brown to reddish-brown outer hairs combined with a silvery-gray, vertically fluted inner wall; the combination is shared with no other common temperate bird's nest fungus[3](https://mushroomidentification.com/encyclopedia/fluted-bird-s-nest) • [4](https://www.mykoweb.com/CAF/species/Cyathus_striatus.html) |
| Peridioles | Typically four or five silvery flattened "eggs" per nest, each 1 to 2 mm across, attached by a funiculus[1](https://www.first-nature.com/fungi/cyathus-striatus.php) |
| Spores | Ellipsoidal, smooth, hyaline, inamyloid, 15-20 × 8-11 µm; basidia usually 4-spored[1](https://www.first-nature.com/fungi/cyathus-striatus.php) |
| Habitat | Saprobic on decaying plant material such as wood chips, small branches, and needles; fruits from early summer to the onset of winter (May to November in Britain and Ireland)[1](https://www.first-nature.com/fungi/cyathus-striatus.php) • [5](https://burkeherbarium.org/imagecollection/taxon.php?Taxon=Cyathus+striatus) |
| Phylogenetic placement | Defines Group VII (striatus group) of the genus *Cyathus*, characterized by a distinctly plicated endoperidium[6](https://pmc.ncbi.nlm.nih.gov/articles/PMC10082518/) |
## Description and identification
The fruiting body is a rigid inverted cone or vase, 7 to 15 mm tall and 6 to 10 mm wide at the flared mouth, narrowing to a small attachment point below, and it almost always occurs in dense clusters, sometimes dozens together on one piece of wood[3](https://mushroomidentification.com/encyclopedia/fluted-bird-s-nest). The outer surface is coated in coarse, shaggy brown to reddish-brown hairs that stand out in tufts and weather away with age, leaving a duller, browner surface[3](https://mushroomidentification.com/encyclopedia/fluted-bird-s-nest). The inner surface, the key character, is silvery gray to lead-gray or brownish and marked with distinct lengthwise grooves running from rim to base[3](https://mushroomidentification.com/encyclopedia/fluted-bird-s-nest).
Young fruitbodies are sealed by a white lid, the epiphragm, initially covered with brown hairs that later fall off; it prevents rain from entering until the peridioles are ripe and often betrays the well-camouflaged fungi by its glint[1](https://www.first-nature.com/fungi/cyathus-striatus.php). A Thai study of six isolates measured funnel-shaped peridia 8.0 to 10 mm high with a mouth diameter of 7.0 to 9.0 mm, peridioles 1.5 to 2.5 mm in diameter that were dark gray to black and ellipsoid or lenticular in outline, and thick-walled basidiospores of 16.0 to 20.0 × 10.0 to 12.0 µm with a wall 2 to 3 µm thick[7](https://microbiologyjournal.org/morphological-and-dna-based-classification-of-cyathus-sp-isolates-from-thailand-basidiomycota-nidulariaceae/).
The species name *striatus* refers to the striate, or ribbed, sides of the cups, and the generic name *Cyathus* comes from the Greek prefix kyath-, meaning cup shaped[1](https://www.first-nature.com/fungi/cyathus-striatus.php).
## Similar species
[Cyathus stercoreus](https://www.edgepedia.org/cyathus-stercoreus) is the main look-alike: it has a smooth, shiny, unstriate inner zone, less bristly outer hairs, a rim that is not so widely flared, and it usually grows on dung[1](https://www.first-nature.com/fungi/cyathus-striatus.php) • [8](https://www.fungipedia.org/en/hongos/cyathus-stercoreus.html). *Cyathus olla* also has a smooth interior and taller fruiting bodies, and *Crucibulum laeve* is another common but hard-to-spot relative[1](https://www.first-nature.com/fungi/cyathus-striatus.php). The combination of a shaggy outer surface and a conspicuously striate inner surface makes *C. striatus* unlikely to be confused with any other bird's nest fungus[4](https://www.mykoweb.com/CAF/species/Cyathus_striatus.html).
## Spore dispersal
Like other bird's nest fungi, *Cyathus striatus* has abandoned wind release of spores and instead uses a rain-powered splash mechanism, with the cup shaped to catch and redirect falling drops[3](https://mushroomidentification.com/encyclopedia/fluted-bird-s-nest). When raindrops slide down the sloping sides of the cup they dislodge the peridioles and eject them from the nest[1](https://www.first-nature.com/fungi/cyathus-striatus.php). Each peridiole is connected to the inner wall by a funiculus, a hollow sheath around a coiled length of interwoven hyphal cord; when the peridiole is ejected the sheath ruptures, leaving a long fine cord attached to a sticky mass of hyphal threads called a hapteron[1](https://www.first-nature.com/fungi/cyathus-striatus.php). If the hapteron strikes a twig, the cord wraps around it and the peridiole rotates until the cord is fully wound up, anchoring the spore-filled packet to a potential food source[1](https://www.first-nature.com/fungi/cyathus-striatus.php).
The splash-cup method ejects peridioles less than 2 m from the basidiome, which limits the dispersal area; as the peridiole wall breaks down, rain washes the spores further away, and small animals that eat the peridioles can also deposit viable spores at a distance[1](https://www.first-nature.com/fungi/cyathus-striatus.php) • [6](https://pmc.ncbi.nlm.nih.gov/articles/PMC10082518/).
## Taxonomy and phylogeny
William Hudson (1730 to 1793) described the species in 1778 as *Peziza striata*, placing it among ascomycete cup fungi; Persoon transferred it to *Cyathus* in 1801, and synonyms include *Nidularia striata* (Huds.) With. and *Cyathella striata* (Huds.) Brot.[1](https://www.first-nature.com/fungi/cyathus-striatus.php) The NCBI taxonomy record gives the current name as *Cyathus striatus* Willd., 1787, with taxonomy ID 68777[9](https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=68777).
A 2023 molecular review of internal clades in *Cyathus* defined seven morphological groups and placed *C. striatus* in Group VII, defined by a distinctly plicated endoperidium, an exoperidium that is sometimes inconspicuous with hirsute to woolly tomentum, and mostly elliptical basidiospores with a tunica present[6](https://pmc.ncbi.nlm.nih.gov/articles/PMC10082518/). The same review cautioned that uncertain sequences for common species such as *C. striatus* are potentially compromising for phylogeny, because herbaria frequently hold specimens identified as *C. striatus* merely because they show striations in the basidiome; the possible existence of a species complex can only be proven with correctly identified specimens matching the type specimen's morphology[10](https://link.springer.com/article/10.1186/s43008-023-00111-y).
## Ecology and chemistry
The fungus is saprobic on decaying plant material, occurring on wood chips, small branches, and needles in a number of different habitats[5](https://burkeherbarium.org/imagecollection/taxon.php?Taxon=Cyathus+striatus). It seems to prefer timber already attacked by other saprobic fungi; in one Welsh woodland observation the fruitbodies swarmed over a long-dead trunk while neighboring fallen trunks in the same area showed none[1](https://www.first-nature.com/fungi/cyathus-striatus.php). Capability for lignin degradation has been reported in *C. striatus*, together with *C. stercoreus* and other *Cyathus* species[2](https://myco-lb.jgi.doe.gov/Cyastr2/Cyastr2.home.html). A genome project, *Cyathus striatus* AH 40144 v1.0, is maintained by the US Department of Energy Joint Genome Institute's Myco-LOCUS resource[2](https://myco-lb.jgi.doe.gov/Cyastr2/Cyastr2.home.html).
All bird's nest fungi, including *C. striatus*, are reported to be inedible; the fruitbodies are too small to offer any food value[1](https://www.first-nature.com/fungi/cyathus-striatus.php).
## References
1. [Cyathus striatus, Fluted Bird's Nest, identification, First Nature](https://www.first-nature.com/fungi/cyathus-striatus.php)
2. [Home - Cyathus striatus AH 40144 v1.0, DOE Joint Genome Institute Myco-LOCUS](https://myco-lb.jgi.doe.gov/Cyastr2/Cyastr2.home.html)
3. [Fluted Bird's Nest (Cyathus striatus) - Identification, Mushroom Identifier](https://mushroomidentification.com/encyclopedia/fluted-bird-s-nest)
4. [California Fungi: Cyathus striatus, MykoWeb](https://www.mykoweb.com/CAF/species/Cyathus_striatus.html)
5. [Cyathus striatus, Burke Herbarium Image Collection](https://burkeherbarium.org/imagecollection/taxon.php?Taxon=Cyathus+striatus)
6. [Rearranging the Bird's Nest Fungi: molecular review of internal clades in Cyathus (Nidulariaceae, Basidiomycota), IMA Fungus (2023)](https://pmc.ncbi.nlm.nih.gov/articles/PMC10082518/)
7. [Morphological and DNA-based Classification of Cyathus sp. Isolates from Thailand, Journal of Pure and Applied Microbiology (2020)](https://microbiologyjournal.org/morphological-and-dna-based-classification-of-cyathus-sp-isolates-from-thailand-basidiomycota-nidulariaceae/)
8. [Cyathus stercoreus, Fungipedia Mushroom Guide](https://www.fungipedia.org/en/hongos/cyathus-stercoreus.html)
9. [Taxonomy Browser: Cyathus striatus, NCBI](https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=68777)
10. [Rearranging the Bird's Nest Fungi: molecular review of internal clades in Cyathus, IMA Fungus, Springer Nature](https://link.springer.com/article/10.1186/s43008-023-00111-y)
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*Topic: Encyclopedia › Life and health › Microorganisms and fungi › Fungi and mycology › Basidiomycete taxa › Agaricomycetes › Gasteroid fungi › Stinkhorns and bird's-nest fungi › Cyathus (bird's-nest genus)*
*Initially written Sep 17, 2026 · Reviewed: Oct 21, 2026 · Edited: Oct 15, 2026; Oct 21, 2026 · Last review: Oct 21, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license