It is worth keeping detailed, written records of any bryophilous fungi as they are so poorly recorded and a huge number known in mainland Europe have not been found in the British Isles, no doubt overlooked.
As with any specimen voucher, note the name of the species (if known), its host or associated mosses and habitat, the date, the site, the UK/I vice county, co-ordinates (lat. long. or preferably UK grid reference. You can learn more about these online and can use a smartphone app to get accurate grid reference readings in the field. Also note the collector’s name and a determiner if somebody else provided the ID of the fungus. Add any other notes you think are important. This information should also be put onto a paper packet containing the specimen.
Storing specimens long term – avoiding fungal contamination
As with bryophytes, bryophilous fungi can be air-dried overnight and then stored in a paper packet for centuries. Toilet paper or kitchen roll can be used to remove excess moisture from specimens before they are set to dry out on top of the labelled packet they will go into (see this https://www.youtube.com/watch?v=n_C7XAPFaBc for one method on making herbarium packets).
If you store specimens in paper or plastic packets without first air-drying them, they will go mouldy and opportunistic fungi you don’t want will smother the specimens, making them useless (based on personal experience). It is therefore very important to process specimens as soon as possible after collection, and not to leave them in damp collecting pots, as generalist moulds will proliferate in even a short time. These cause problems not only when examining the host-fungal interface, but can also cause specimens to be useless when it comes to sequencing, as non-target DNA will smother the signal from the target.
Sub-packeting
While analysing a collection, an excellent habit to get into is sub-packeting. This involves making separate smaller paper packets containing fragments of interest. For example, a large collection of a pleurocarpous moss might have a region with many fruitbodies of a fungus. A fragment from such a region can be stored in the main packet separately, where it is then easy to refind the fungus in future studies of the material. If this isn’t done, then finding a fungus again can be like searching for a needle in a haystack. Sometimes, invertebrates can destroy samples by eating apothecia of some fungi and searching can be fruitless. Other times, the fungi are so specialised and difficult to find that one could spend days finding something that has already been shown to be present in the sample. Sub-packets are also extremely useful for setting aside material for DNA barcoding.
Pest control
Bryophytes are frequently crawling with life, including invertebrates like mites and springtails. While mostly harmless, with most dying when desiccated, some of these invertebrates can be hugely problematic in fungal collections. Apothecioid fungi like Octospora and Bryoscyphus seem to be particularly vulnerable to springtails, which feast on the fleshy, unprotected hymenium. I have been told of cases where specimens are kept damp in polythene bags during postage, only to arrive at the recipient lacking the apothecia that were expected. Instead, gluttonous springtails bound around the husks of the apothecia.
Some springtails and other invertebrates can survive desiccation and hunt through herbarium packets, likely consuming any soft fungal material and also the dead tissues of other invertebrates. Freezing groups of specimens is recommended. Placing paper packets of dry specimens into airtight plastic food bags (important as this prevents moisture from getting inside and ruining the specimens; double-bagging is recommended if there is any doubt) and freezing them for at least a few days, if not longer, is useful good practice as one’s collection expands. In my experience, this has negligible effects on the plant or fungal tissue for re-analysis and also DNA barcoding. Some institutions recommend two cycles of freezing and thawing after infestations. The logic is that invertebrates produce hardy eggs that can survive adverse conditions. Upon the first thaw, the eggs will hatch and renew the infestation. The second freezing procedure then acts to kill these eggs.
It is also worth removing or killing any invertebrates that are seen on samples when they are initially examined in the living state. Any that are left could become problematic in the future. Washing larger samples under a running tap, or shaking them outside, could help dislodge some invertebrates.
Bryophilous fungi 