Fluted Bird’s Nest Fungus Cultivation Project

July 2, 2025

Taxonomy and Classification

Carl Ludwig Willdenow

Cyathus striatus, commonly known as the fluted bird’s nest fungus, belongs to the family Nidulariaceae. It was originally described in 1778 by William Hudson as Peziza striata and later reassigned to the genus Cyathus by Carl Ludwig Willdenow in 1787. The species name “striatus” is derived from the Latin word stria, meaning “grooves” or “fine ridges”, referring to the distinctive striated inner surface of the fruiting body.

Macroscopic Morphology

From Jamie Kingscott on Inaturalist

The fruiting body of Cyathus striatus resembles a miniature bird’s nest and typically measures between 7-10mm in height and 6-8mm in width, though specimens up to 15mm are known. The structure is vase-like/shaped like an inverted cone. Its outer surface, known as the exoperidium, ranges from grayish buff to deep brown and is covered in a shaggy or hairy texture referred to as tomentum, with hairs pointing downward. The inner surface, or endoperidium, is shiny and marked with vertical grooves or striations. In immature specimens, the cup is covered by a thin membrane called an epiphragm, which is also hairy. As the fruiting body matures, this membrane deteriorates and eventually falls away, exposing the structures inside.

Peridioles and Internal Structure

By Robert Sasata licensed under CC BY-SA 3.0

Inside the cup are small, disc-shaped bodies called peridioles, typically ranging from 1 to 1.5 millimeters in diameter, and occasionally reaching 2 millimeters. These structures resemble tiny eggs and are responsible for housing the spores. When young, peridioles may appear drab gray due to the presence of a thin outer membrane called the tunica. Each peridiole is connected to the cup wall by a structure known as a funiculus, which is a complex cord of mycelium. The funiculus is composed of three regions: a basal piece that attaches to the cup wall, a middle section, and a sheath-like upper portion called the purse that attaches to the underside of the peridiole. Inside the funiculus is a coiled funicular cord, which terminates in an adhesive structure called the hapteron.

Spore Dispersal Mechanism

From "Splash and grab: Biomechanics of peridiole ejection and function of the funicular cord in birds nest fungi" licensed under CC BY 3.0

Cyathus striatus disperses its spores through a splash-cup mechanism. When raindrops strike the interior of the cup with sufficient force and at the proper angle, they eject the peridioles into the air. The motion uncoils the funicular cord, and the hapteron at the end may stick to a nearby object, such as a twig or blade of grass. As the peridiole continues to move, it wraps the cord around the object, anchoring it in place. Over time, the peridiole either breaks down and releases the spores or is ingested by animals and redeposited through their digestive tract.

Life Cycle

Cyathus striatus can reproduce both sexually and asexually. During sexual reproduction, the basidiospores each containing a single haploid nucleus germinate and form monokaryotic hyphae. When hyphae of compatible mating types meet, they undergo plasmogamy to form dikaryotic mycelium. Under favorable conditions, this dikaryotic mycelium gives rise to new fruiting bodies. Within these structures, basidia are formed, and compatible nuclei inside the basidia fuse to create a diploid nucleus. This nucleus then undergoes meiosis to produce new haploid basidiospores, continuing the cycle

Habitat and Distribution

This species is saprobic, deriving nutrients from decaying organic material such as dead wood, mulch, and woody debris. It is typically found growing in small clusters in moist environments and is more frequently observed in shallow depressions than in elevated or drier areas. Cyathus striatus is widespread across temperate regions, including North and South America, Europe, Asia, Central America, and New Zealand. Fruiting occurs primarily from summer through early winter. It is also commonly seen in urban settings, especially in mulched garden beds.

Similar Species

Cyathus stercoreus is a similar species often found growing on dung. Unlike C. striatus, it lacks the characteristic striated inner surface of the cup.

Bioactive Compounds

Cyathus striatus has been found to produce a number of bioactive chemical compounds. It was first reported in 1971 to contain indolic substances, and later studies identified these as striatins A, B, and C. These compounds have shown antibiotic activity against various fungi and both Gram-positive and Gram-negative bacteria. The fungus also produces a group of diterpenoid antibiotic compounds known as cyathins, as well as sesquiterpenes such as schizandronols. Several triterpenes have also been isolated, including glochidone, glochidonol, glochidiol, glochidiol diacetate, cyathic acid, striatic acid, cyathadonic acid, and epistriatic acid. Many of these were first discovered through chemical analysis of this species.

Already Documented Cultivation of Cyathus striatus

Project Diary Entries (still ongoing check back for updates)

Aug 1st, 2025 "I acquired a Cyathus striatus culture on May 27, 2025 from Mycelium Emporium. It has been in storage since then due to issues in my personal life and with Southern Spore as a business. However I intend to finally start my cultivation attempt next week. First steps will be growing it out on agar and creating a master liquid culture. I also need to organize all my research and formulate a solid plan for creating spawn and then the eventual fruiting. Currently i'm thinking of casting a wide net in terms of growing techniques. I want to do both indoors and outdoors cultivation. Will most likely making a short form video going through the plan next week. Need to make sure i'm capturing footage for the long form youtube video I want to make on this. Im fairly optimistic that i can get it to fruit successfully due to the already documented cultivation of birds nest fungi. My main reason for starting this project is I honestly think i have better odds of growing birds nest fungi than actually finding it in the wild. I just want to see the peridioles fly when hit with a water droplet."