Small to medium agaric, growing on the ground, litter, mulch or dung, rarely on wood or bryophytes, with a typically rusty brown, or otherwise cinnamon-brown or dark reddish brown spore print. Fruit-body fragile and often collapsing with age (but not truly deliquescent). Pileus pale, yellow, red or pink, green or grey, rarely white or brown; viscid or glutinous. Lamellae adnexed or adnate at first, but typically free at maturity. Stipe central. Partial veil remnants absent. Spores yellow-brown or reddish brown, smooth; with broad germ pore. Cheilocystidia present. Pileipellis a hymeniderm (or misinterpreted as an epithelium). Clamp connections absent.

The fragile fruit-body with pleated pileus margin can resemble Parasola (and other segregates of Coprinus) and Psathyrella, but all of these have very dark to black spores. Other small to medium, brown-spored agarics often have a partial veil (as in Cortinarius) and/or warty spores (as in Galerina, which also usually has a plage on the spores). The viscid pileus of Bolbitius is distinctive, and is present only rarely in genera that share a hymeniform pileipellis such as Agrocybe, Conocybe or Pholiotina. In addition, these three genera usually possess clamp connections and sometimes an annulus; and in Agrocybe the spore print is typically dark brown. Otherwise, among the genera with smooth, brown spores and no volva or partial veil, a viscid pileus is present only in Inocybe and Psilocybe, which both have a cutis.

The commonest species, Bolbitius titubans, often grows in lawns and has a pileus that, when young, is bright yellow and rather parabolic.

Bolbitius Fr., Epicr. Syst. Mycol. 253 (1838).

Several species: Bolbitius coprophilus, B. muscicola and B. titubans, with var. titubans (= B. vitellinus) and var. olivaceus (= B. variicolor).

W.A., S.A., Qld, N.S.W., Vic. and Tas. (and probably also N.T.).

Common in lawns and gardens, occasional in native forests.

On the ground, in lawns, and on litter, mulch or dung, rarely on wood or bryophytes (B. muscicola).

Saprotrophic.

Arnolds, E. (2005), Bolbitius, in M.E. Noordeloos, T.W. Kuyper & E.C. Vellinga (eds), Flora Agaricina Neerlandica, Volume 6, 112–119. CRC Press, Boca Raton. [Description, B&W Illustration and Microcharacters of B. coprophilus and B. titubans along with Key to the five Dutch species]

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 B. titubans (as B. vitellinus) and B. titubans var. olivaceus]

Bougher, N.L. & Syme, K. (1998), Fungi of Southern Australia. University of Western Australia Press, Nedlands. [Description, Illustration and Microcharacters of B. titubans (as B. vitellinus and as B. variicolor)]

Breitenbach, J. & Kränzlin, F. (eds) (1995), Fungi of Switzerland. Volume 4. Agarics 2nd part. Edition Mykologia, Lucerne. [Description, Microcharacters and Illustration of B. titubans (as B. vitellinus)]

Fuhrer, B. (2005), A Field Guide to Australian Fungi. Bloomings Books, Hawthorn. [Description and Illustration of B. muscicola and B. titubans (as B. vitellinus)]

Grey, P. & Grey, E. (2005), Fungi Down Under. Fungimap, South Yarra. [Description, Illustration and Map for B. titubans (as B. vitellinus)]

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. [Description and Microcharacters of B. titubans (also as B. vitellinus)]

McCann, I.R. (2003), Australian Fungi Illustrated. Macdown Productions, Vermont. [Illustration of B. titubans (as B. vitellinus)]

Taylor, M. (1981), Mushrooms and Toadstools. A.H. & A.W. Reid, Wellington. [Illustration of B. muscicola from New Zealand]

Watling, R. (1982), British Fungus Flora. Agarics and Boleti. 3 / Bolbitaceae: Agrocybe, Bolbitius & Conocybe. Royal Botanic Garden, Edinburgh. [Description, B&W Illustration and Microcharacters of B. coprophilus, B. titubans (also as B. vitellinus and B. variicolor) along with Key to British species]

Watling, R. & Taylor, G.M. (1987), Observations on the Bolbitiaceae: 27. Preliminary account of the Bolbitiaceae of New Zealand, Biblioth. Mycol. 117: 1–61. [Description, Microcharacters and B&W Illustration of B. muscicola and and B. titubans (and as B. vitellinus) from New Zealand]

Young, A.M. (2005b), A Field Guide to the Fungi of Australia. University of New South Wales Press, Sydney. [Description and Illustration of B. titubans (as B. vitellinus)]