On the Trail of a Glowing Outlier
Finding Mycena chlorophos aka Green Pepe at Sungai Congkak
Also known as: Green Pepe, Yakō-také, 夜光菇
I first came across Mycena chlorophos behind a computer screen while writing a piece for The Mushroom Magazine titled A Luminous Pursuit. At the time, I was looking for glowing mushroom photos to accompany the story and stumbled on a remarkable image by Michelle Honey, taken in Australia. That photo stayed with me.
Years later, after more than a few misidentifications involving white Mycena look-alikes, I found myself at Sungai Congkak with friends.
At the very end of our foray, just before giving up, I took one last look at a pile of wood near the riverbank. There it was, growing from a shard of bamboo. We’d found the real thing.
Later that night, even before turning the lights off, I noticed the mushrooms glowing clearly inside their container. Without a doubt, they were the brightest mushrooms I’d ever seen.
Other species I’ve photographed often require minutes of long exposure to catch their faint glow. But M. chlorophos is different.
Some photographers report using surprisingly low ISOs and short shutter speeds (~20 to 30 seconds) to capture its luminescence. The intensity caught me off guard.
Its glow comes from a luciferin–luciferase reaction, producing green light at roughly 520–530 nm.
The cap of Mycena chlorophos is small and bell-shaped, typically measuring no more than 2 cm in diameter, and is pale gray-brown when moist, fading to a whitish color as it dries.
Its gills are adnate to slightly decurrent, and the slender, hollow stipe glows along with the cap. Spores are white, smooth, and ellipsoid; when fresh, the entire mushroom often feels sticky to the touch.
Breaking Down the Name
The genus name Mycena comes from the Greek mykēs, meaning “fungus” or “mushroom.” The species name, chlorophos, combines chloros (χλωρός), meaning “green,” with phos (φῶς), meaning “light.”
Put together, the name translates quite literally to “green light.”
Names, Myths, and Regional Sightings
In the Pacific Islands, Mycena chlorophos is sometimes called Green Pepe—a name believed to come from Melanesian dialects, where pepe refers to small mushrooms or, in some folklore, to ghost lights or forest spirits.
In certain traditions, glowing fungi are tied to omens, sacred places, or forest guardians.
In Japan, it’s called ヤコウタケ (Yakō-také), the “night-light mushroom,” while in Taiwan it’s known as 夜光菇, literally meaning “glow-in-the-dark mushroom.”
You’ll find Mycena chlorophos across tropical and subtropical forests from Malaysia and Indonesia to Japan, Taiwan, Sri Lanka, Brazil, and parts of Australia. It prefers the damp decay of fallen logs, palm trunks, or bamboo, typically emerging after a good rain.
awesome write-up and pictures :)