Panaeolus cyanescens: a different genus, and what its black spores look like under the microscope

01A different genus

Panaeolus cyanescens, still sometimes listed under its older name Copelandia cyanescens, is a small, pale, dung-associated mushroom of the tropics and subtropics. It sits in the genus Panaeolus, which is separated from Psilocybe by, among other things, the colour of its spores: Panaeolus spores are black in mass rather than purple-brown. The species was described from Sri Lanka in the 1800s and is now known across Australia, Southeast Asia, the Pacific, the Caribbean and the Gulf Coast of the United States.

02Under the microscope

This is the specimen that teaches you spore colour. Panaeolus cyanescens spores are jet black in the print and dark, opaque and lemon-shaped to broadly ellipsoid on the slide, with a distinct germ pore. They run slightly larger than cubensis, and their opacity means the cell wall is harder to resolve than in a pale Psilocybe spore. A Pan Cyan print beside a cubensis print on the same sheet of foil is the fastest way to learn what "black" versus "purple-brown" actually means, and it is why the library keeps the Pan Cyans as their own collection.

Panaeolus prints tend to be thin and patchy because the caps are small. The library's isolates are collected with that in mind.

03The isolates in the Pan Cyans collection

• Pan Cyan Byron Bay iso, a What The Fungi isolation from a New South Wales collection.
• Pan Cyan Eungai "Red Spore" iso, from the Eungai area of New South Wales, named for the unusual colour of its deposit.
• Pan Cyan Eungai "Iceberg Isolate", a pale isolation from the same locality.
• Pan Cyan TTBVI, a long-established isolate from Tortola in the British Virgin Islands.

Place names on these cards are collection localities, which is the convention for wild-derived lines: the name tells you where the founding specimen came from.

04Telling Pan Cyan from cubensis on a slide

1. Make a print first. Black means Panaeolus; purple-brown means Psilocybe.
2. At 400x, look at opacity. Panaeolus spores are dark and solid-looking; cubensis spores are translucent brown.
3. At 1000x, measure. Pan Cyan spores are a little larger and more lemon-shaped.
4. Record both on the same page. The comparison is worth more than either measurement alone.