The underlying data matrix for FunKey is enormous. There are 159 taxa (covering 112 genera), coded for 115 characters, of which seven are measurement characters, and 108 are multistate characters (with 383 character states). This means that there are more than 18,000 taxon/character combinations and 60,000 taxon/character state combinations. Each taxon/character state combination is coded as either: present (with options common or rare), absent, uncertain, misinterpreted (with options commonly or rarely) or not scoped. This data matrix was constructed de novo for FunKey.

Information on the character states of each genus was built up by consulting descriptions of individual species. We did not work directly from generic descriptions, because they often did not cover all the characters used, and the circumscription of some genera has changed greatly in recent years. Also, generic descriptions in floras and monographs, particularly as presented in keys, often simplify the variation in character states that is actually present in the genus. By taking information from all the individual species of each genus, the character states hopefully reflect the full range of variation that will be encountered in each genus.

Information on the character states of each genus came from scanning literature on all species of each of the agaric genera that are reliably recorded from Australia (totaling 1044 species). One or more descriptions of each species were utilised, from a variety of published sources, chosen from those listed in May & Wood (1997) and May et al. (2003; 2004) and recent literature. The descriptions in Grgurinovic (1997a) and Bougher & Syme (1997) were particularly useful, being comprehensive and based on examination of Australian material. For cosmopolitan species, use was made of the descriptions in Fungi of Switzerland, the British Fungus Flora and Flora Agaricina Neerlandica. For tropical species, the floras of Pegler (1977; 1983c; 1986) for East Africa, the Lesser Antilles and Sri Lanka were very useful.

The species utilised in coding up character states are those listed under each genus in the taxon fact sheets. All the references that were consulted in drawing up the character states for each genus are included in the list of references under each genus in the taxon fact sheets. Fresh and herbarium material, mainly at the National Herbarium of Victoria (MEL), was also examined in coding up the character states.

The particular character states for each genus reflect the variation among Australian species only, and are a subset of the variation possible in the genus as a whole. Sometimes the Australian species cover the full range of variation in a given character, sometimes not. The use of data from only Australian species means that the contrast between some genera is accentuated. However, FunKey works surprisingly well for agarics from other countries, although some genera absent from Australia but present elsewhere are obviously missing from the key.

Once a preliminary key was constructed, it was tested against other published descriptions and fresh material to check that the character states reflected the full range of variation to be expected in each genus.

Coding of the character states was deliberately broad. If a description indicated that the pileus was somewhat hygrophanous, indicating that it could be difficult to discern whether it was hygrophanous or not, then in the key, both the states yes and no are coded for the character Pileus hygrophanous. This means that sometimes taxa are retained in the key when you might expect them to be discarded, based on the character states most commonly observed in the particular taxon. However, our approach of deliberately making sure that the coding covers all known variation means that it is less likely that taxa are excluded during an identification session.

With such a large data matrix there are bound to be some errors and omissions. We value feedback on FunKey, particularly in relation to specimens that do not key to the correct genus.