A spore print is a fundamental tool for mushroom enthusiasts and mycologists. It involves collecting the powdery deposit of spores from a mushroom’s cap onto a surface. This technique allows for the observation of spores en masse, revealing their color, which is often imperceptible when viewing individual spores.
Why Create a Spore Print
Making a spore print primarily aids in mushroom identification. Spore color is a distinguishing characteristic, as different mushroom species produce spores in a range of colors, including white, black, brown, pink, and green. While two mushrooms might appear visually similar, their spore colors can differ, providing important information for accurate identification.
Beyond identification, spore prints are also useful in mushroom cultivation. The collected spores can be used to germinate new mycelium, the vegetative part of a fungus, by transferring them to a sterile growth medium. Spore prints can also be used to create spore syringes, which are then employed to inoculate substrates for growing mushrooms. Furthermore, they preserve the genetic material of a specific mushroom strain for future use or sharing.
Step-by-Step Spore Printing
Creating a spore print involves a few simple steps, beginning with the selection of a suitable mushroom. Choose a mature mushroom that is actively releasing spores, as very young or old specimens may not yield a good print. Mushrooms with visible gills, the spore-bearing structures underneath the cap, are ideal for this process.
To prepare the mushroom, carefully remove the stem, or stipe, right up to the cap so it lies flat. This ensures the gill surface makes direct contact with the printing surface. If you prefer not to separate the cap from the stem, make a small hole in paper or an index card, slide the stem through, and rest the cap on the surface.
Next, select your printing surface. Options include aluminum foil, glass, or paper. Using both black and white paper, with the mushroom cap placed half on each, can be beneficial, as it helps to visualize spores of any color. For instance, white spores are more apparent on a dark background, while dark spores stand out on white paper.
Place the mushroom cap, gills facing down, onto your chosen surface. To encourage spore release and prevent air currents from dispersing spores, cover the mushroom cap with a bowl, glass, or paper cup. Adding a single drop of water to the top of the mushroom cap can facilitate spore release.
Allow the mushroom to sit undisturbed for 2 to 24 hours, or overnight. The exact duration depends on the mushroom’s freshness and environmental humidity. A still environment helps ensure a clear, distinct print. After the waiting period, carefully lift the covering and gently remove the mushroom cap to reveal the spore print.
After Making Your Spore Print
Once a spore print is successfully made, it is important to handle it with care as it is delicate and easily smudged. The print will appear as a powdery deposit, often reflecting the mushroom’s gill pattern. The color of this deposit is the primary information for identification.
To preserve the print for long-term use, lightly spray it with an artist’s fixative or hairspray. Hold the spray can approximately 12 to 15 inches away from the print to ensure even application and prevent spores from being blown away. This protective layer helps prevent smudging and maintain the print’s integrity.
For storage, allow the fixative to dry completely, then carefully fold the paper or place the foil print into a sealed bag or envelope. Label the print with the mushroom species, if known, and the date it was collected. Store the preserved spore prints in a cool, dry, and dark place, such as a refrigerator, to maintain their viability and prevent moisture damage. Stored properly, spore prints can remain viable for a year or more, with some sources suggesting up to two years or longer under optimal refrigerated conditions.