Spore identification under a microscope

What to look at

Five features describe a spore. Look at each one in turn, in the same light and at the same magnification.

• Size. Length and width, measured in micrometres.
• Shape. The outline, such as oval or nearly round.
• Colour. Clear, or a shade of brown or purple-brown. Colour changes with the light.
• Wall. How thick the outer layer looks, and whether it has more than one layer.
• Germ pore. A small thin area in the wall, often near one end. It is not always easy to see.

How spore appearance is described

Mycologists use a small set of fixed words. Ellipsoid means a broadly oval outline. Subellipsoid means almost oval, with a slight difference in outline. Hyaline means colourless.

Sizes are given as a range in micrometres, length first and width second. A ratio called Q is length divided by width. A Q near 1 describes a nearly round spore. A higher Q describes a longer one.

State how the sample was mounted. Drying and the mounting liquid can change the size you measure.

Why strains of one species look alike

Psilocybe cubensis is one species. Names such as Golden Teacher or B+ are strain names within that species. They are informal names, not separate species.

The shop’s strain guides say that microscopic appearance alone cannot reliably confirm a specific strain. A strain name does not promise a different spore shape, colour or size range.

Preparation also changes what you measure. In one published study, drying cut the length of one species’ spores by 10 percent. It cut the width by 16 percent. Two samples can differ because of handling, not strain.

How to record what you see

Use one record sheet for every sample. Write down:

• the date and a label for the sample
• the objective and the total magnification
• the mounting liquid
• the calibration value for that objective
• the number of spores measured
• notes on shape, colour, wall and germ pore

Keep the light and the magnification the same for every sample you compare. A photograph helps if you have a camera adapter or phone clip.

Strain guides

Each guide applies these steps to one named strain. None claims that microscopy alone can name a strain.

• Golden Teacher
• B+
• Jedi Mind Fuk
• Albino A+
• Penis Envy
• Aztec God
• Blue Meanies
• Tidal Wave
• Yeti
• Bluey Vuitton
• Cambodian Gold
• McKennaii
• Brazil Corumba
• Melmac