Small to very large agaric, growing on the ground, with a rusty to ochre-brown or sometimes clay-brown spore print. Pileus white, pale, yellow, orange, brown, green, purple or grey, dry, viscid or rarely glutinous, smooth, radially fibrillose or sometimes pruinose, squamulose or with felty patches. Lamellae adnexed, adnate, sinuate or notched, rarely subdecurrent. Stipe central, not viscid or glutinous. Partial veil remnants a ring zone or rarely absent (and then cortina present when young). Volva rarely present. Spores yellow-brown, warty; plage absent; germ pore absent. Cheilocystidia present or absent, but then usually clavate, and never with modified apices. Lamellar trama regular. Pileipellis a cutis or a trichoderm. Clamp connections present.

The cobwebby partial veil (best observed on young fruit-bodies) in combination with an ochre to rusty brown spore print and warty spores is characteristic for Cortinarius. Among brown-spored genera with warty spores, Hebeloma differs in the constant presence of cheilocystidia and a viscid pileus, and it has a clay-brown or pinkish brown spore print. Galerina generally has a plage on the spores, and cheilocystidia. Gymnopilus is almost always found on wood or litter and invariably has cheilocystidia. Tubaria has smooth spores (at least in Australian species) and cheilocystidia, and the partial veil is sometimes membranous. Phaeocollybia has a pseudorhiza and cheilocystidia. Where cheilocystidia are present in Cortinarius, they are usually clavate, and never capitate as they can be in Galerina, Gymnopilus and Phaeocollybia. The smooth-spored Inocybe can have a cortina, but it generally has a clay-brown rather than ochre spore print, and in addition the pileus is rather scaly or radially fibrillose, the spores can be nodulose, and thick-walled cystidia are often present.

A few species included in Cortinarius (other) have a submembranous partial veil, and are close to those keyed out separately in Cortinarius morphogroup Rozites, where the partial veil is membranous and produces an annulus on the stipe, rather than the ring zone that is present in most species of Cortinarius. Other segregates of Cortinarius that are keyed out separately are: morphogroup Cuphocybe (partial veil remnants not evident on the stipe but with patches of felty scales on the pileus) and subgenera Cortinarius (dry, deep purple pileus and stipe and very dark lamellae), Dermocybe (bright colours, anthraquinone pigments that react to KOH and often with a banded lower stipe) and Myxacium (pileus and stipe viscid or glutinous). Members of subgenus Dermocybe are often bright red, orange or yellow, but some of the brown species are very difficult to separate from other Cortinarius without information on the chemical composition of the fruit-bodies. Members of subgenus Myxacium are indistinguishable from other Cortinarius if the pileus and stipe have dried and become non-glutinous. Cortinarius australiensis is keyed out separately due to the massive size and membranous partial veil, as are C. canarius (bright yellow fruit-body and very finely ornamented spores), C. fibrillosus (radially fibrillose pileus and very finely ornamented spores) and C. mariae (greenish spore print and smooth spores).

Many species (around 120 described, including truffle-like species, eventual number could be several hundred).

Australian species are distributed below among traditional morphologically defined subgenera (several of which are in fact not supported as phylogenetic units) as follows:

Subgenus Cortinarius (pileus and stipe dry, violet, cheilocystidia and pleurocsytidia present, spores sometime with plage present). This group is keyed out separately.

Subgenus Dermocybe (pileus typically radially fibrillose and dry or it can be viscid, often brightly-coloured red, orange, yellow or green, reacting strongly to KOH, stipe dry, with bands of tissue below cortina remnants). This group is keyed out separately.

Subgenus Myxacium (pileus and stipe glutinous). This group is keyed out separately.

Subgenus Phlegmacium (small to typically larger fruit-bodies, often tricholomatoid, with pileus usually viscid or glutinous and not hygrophanous and stipe dry): C. abnormis, C. australiensis (keyed out separately due to massive size and presence of an annulus), C. australis, C. austrosaginus, C. austrovaginatus, C. bambrus, C. caeruleoeburneus, C. capsicosmus, C. chrysochalybdeus, C. chrysopocos (pileus tacky, stipe slippery), C. coelopus, C. fragilipes, C. fucatus, C. fulvoiubatus, C. grantalius, C. ianthinus, C. ingratiolens, C. kilpanius, C. lavendocaeruleus, C. lavendulensis, C. lilacinofulvus, C. memoria-annae, C. nijerrus, C. ochraceofulvus, C. persicanus, C. phaeouranus (pileus slightly tacky), C. phalarus, C. pseudoclaricolor, C. pseudoporphyropus, C. rubescens, C. salmaster, C. subsciorophyllus, C. sublargus (= C. radicatus), C. ulematus, C. violaceohinnuleus and C. wirrabara. Also some poorly known species such as C. basibulbosus.

Subgenus Telamonia (fruit-body small to large, pileus usually hygrophanous and not viscid): C. ardesiacus (‘telamonioid’), C. areolatoimbricatus, C. austropallescens, C. austrotorvus (‘telamonioid’), C. castaneofulvus, C. controversus (doubtfully a Telamonia), C. fibrillosus (keyed out separately due to very fibrillose pileus and almost smooth spores), C. kiambramensis, C. vinaceocinereus, C. vinosipes and C. yerillus. Several poorly known species such as: C. veronabrunneus.

Unplaced (or in smaller subgenera such as Inoloma, Leprocybe, Orellani and Sericeocybe): C. austrocyanites var. brunyensis (dry pileus covered by mat of yellow-brown fibres), C. eartoxicus (Orellani), C. rozites (Inoloma), C. sclerophyllarum (pileus dry, hygrophanous), C. tasmacamphoratus (Sericeocybe) and C. vinaceolamellatus (Sericeocybe but keyed out separately in Cortinarius morphogroup Rozites due to the membranous annulus).

Species formerly in the separate genera Cuphocybe (with squamulose pileus), Rapacea (Cortinarius mariae, with greenish spore print and very finely ornamented spores) and Rozites (with membranous annulus) are also keyed out separately.

Also numerous undescribed species.

There are a number of other Australian species in the genus which are sequestrate (truffle-like), often formerly placed in the genus Thaxterogaster, and also some truffle-like relatives currently placed in Protoglossum, Quadrispora and Timgrovea.

All States and Territories.

In native forests, across a wide range of vegetation types from dry mallee woodland to cool-temperate rainforest. A few species also occur with exotic trees such as oak.

On the ground.

Ectomycorrhizal.

Bougher, N.L. (2009a), Fungi of the Perth region and beyond: a self-managed field book, Western Australian Naturalists' Club (Inc.), Perth. [Description and Illustration of C. ochraceofulvus and C. phalarus]

Bougher, N.L. & Hilton, R.N. (1989), Three Cortinarius species from Western Australia, Mycol. Res. 93: 424–428. [Description, B&W Illustration and Microcharacters of C. lavendulensis and C. phalarus]

Bougher, N.L. & Syme, K. (1998), Fungi of Southern Australia. University of Western Australia Press, Nedlands. [Description, Illustration and Microcharacters of C. phalarus and C. lavendulensis]

Fuhrer, B. (2005), A Field Guide to Australian Fungi. Bloomings Books, Hawthorn. [Description and Illustration of C. abnormis, C. areolatoimbricatus, C. aff. largus, C. lavendulensis, C. sublargus and half a dozen unnamed species ]

Fuhrer, B. & Robinson, R. (1992), Rainforest Fungi of Tasmania and South-east Australia. CSIRO Press, East Melbourne. [Illustration of several unnamed species of Cortinarius]

Gasparini, B. (2001b), Cortinarius vinosipes Gasparini sp. nov., Australas. Mycol. 20: 87–91. [Illustration, Description and Microcharacters of C. vinosipes]

Gasparini, B. (2004), Cortinarius subgenus Orellani in Australia and in the world, Australas. Mycol. 23: 62–76. [Description, Illustration and Microcharacters of C. eartoxicus and Description and Microcharacters of C. catarracticus]

Gasparini, B. (2007b), Genus Cortinarius, subgenus Phlegmacium in Tasmania, New Zealand J. Bot. 45: 155–236.[B&W Illustration, Description, Microcharacters and Key for around 25 species in subgenus Phlegmacium from Tasmania. mostly newly described. Note that in this paper Gasparini used a modified concept of Phlegmacium, integrating data on molecular phylogeny, which means that he included in the subgenus species that on morphology alone are treated in FunKey under other subgenera such as Myxacium and in the morphogroup Rozites]

Gasparini, B. & Soop, K. (2008), Contribution to the knowledge of Cortinarius [Agaricales, Cortinariaceae] of Tasmania (Australia) and New Zealand, Australas. Mycol. 27: 173–203. [Description, Microcharacters and Illustration of C. ardesiacus, C. austrotorvus, C. controversus, C. rozites and C. tasmacamphoratus, and key to Australian and New Zealand species dealt with in the publication]

Grey, P. & Grey, E. (2005), Fungi Down Under. Fungimap, South Yarra. [Description, Illustration and Map for C. sublargus]

Grgurinovic, C.A. (1997a), Larger Fungi of South Australia. The Botanic Gardens of Adelaide and State Herbarium and The Flora and Fauna of South Australia Handbooks Committee, Adelaide. [Key to more than 20 South Australian species, and Description and Microcharacters of the species, along with Illustration of C. areolatoimbricatus, C. basibulbosus, C. cinnamoneobadius, C. ianthinus, C. lavendocaeruleus, C. veronabrunneus, C. vinaceocinereus and C. violaceohinnuleus]

McCann, I.R. (2003), Australian Fungi Illustrated. Macdown Productions, Vermont. [Illustration of C. abnormis and C. sublargus (as C. radicatus), as well as several unidentified species]

Watling, R., Gill, M., Giménez, A. & May, T.W. (1992), A new styrylpyrone-containing Cortinarius from Australia, Mycol. Res. 96: 743–748. [Description, B&W Illustration and Microcharacters of C. abnormis]