In order to confidently identify bryophilous fungi, one must study them under the compound microscope. Given that there are several cryptic species, IDs are only tentative based on field observations.
It is highly recommended that anyone wishing to seriously study these fungi use an oil immersion lens on their microscope, giving a total magnification of 1000X. If not, distinctive features and small spores will be difficult to see and measure accurately. That leads on to the point that one should fit (and calibrate) a graticule to their microscope. This isn’t overly difficult and more experienced microscopists are often willing to give advice. One can also use a stage micrometer to calibrate a programme like imageJ to make measurements on a computer.
For bryophilous fungi, the highest magnifications (400X and 1000X) are the only frequently used. I find that it is unlikely that I’ll get away without using oil immersion to study a collection, and this increased magnification is the best way to accurately measure structures and to take better quality photographs / drawings of what I see.
Most of the micrographs on the species image collection on this site were taken while using an oil immersion lens. While I am not going to explain how to set that up, I will say that it is important to clean your 100X lens after use with lens cleaning tissue, and occasionally use some ethanol or isopropanol to aid in removing it right after use. If not, the oil can harden and damage the lens, and the image becomes poor. Also make sure that you don’t get oil on your 40X objective lens if you use a lot of it, else you may have the same problem. Clean both semi-regularly.
Some notes:
- Asci are often variable in shape and size. Try to measure the lengths and widths of asci containing full suites of mature ascospores rather than developing ones or empty ones.
- Try to examine the bases of the asci and any sterile filaments among them. E.g., If the collection has paraphyses: do the paraphyses branch? Do they contain pigments or vacuolar bodies? Are the tips swollen?
- Try to measure the lengths and widths of at least 10 ascospores per collection. Are the spores septate? How variable are they? Have you broken any during the specimen preparation? If you’ve stained them, be aware that they may shrink and / or deform.
- Keep good notes – labelled folders in computers for photos; annotated notebooks for diagrams, measurements, etc.
Bryophilous fungi 