Early treatments of Mortierellaceae, a classical family of the Mucorales, included only two genera, Herpocladium and Mortierella (Schröter, 1893; Fischer, 1892). Dissophora and Haplosporangium, described by Thaxter in 1914, were added to the family by many later students of Mucorales (Hesseltine, 1955; Benjamin, 1959, 1979; Hesseltine and Ellis, 1973). Herpocladium was regarded as a doubtful genus by Hesseltine (1955). Gams (1977) divided Mortierella into two subgenera and nine sections; Benjamin (1978) described the third subgenus of Mortierella, Gamsiella. Other genera added to the family or segregated from Mortierella include Actinomortierella (Chalabuda, 1968), Aquamortierella (Embree and Indoh, 1967), Azygozygum (Chesters, 1933), Echinosporangium (Malloch, 1967), now a synonym of Lobosporangium (Benny and Blackwell, 2004), Micromucor (Gams, 1977, as subgenus; von Arx, 1982, to Mucoraceae as genus), and Umbelopsis (Amos and Barnett, 1966). Trappe and Schenck (1982) suggested the removal of Modicella (Kanouse, 1936; Gerdemann and Trappe, 1974) to Mortierellaceae from Endogonaceae because of its acolumellate sporangia and apparent saprobic habit. A few years ago, Cavalier-Smith (1998) proposed a new order, Mortierellales, which now contains one family, Mortierellaceae, and six genera (Aquamortierella, Dissophora, Gamsiella, Lobosporangium, Modicella, Mortierella)
With the elevation of Gamsiella to generic status (Benny and Blackwell, 2004) and the synonymy of Micromucor with Umbelopsis (Umbelopsidiaceae, Mucorales; Meyer and Gams, 2003), the genus Mortierella, as conceived by Gams (1977) is left with nine sections and no subgenera.
Mortierellales A. Fischer, 1892 (In Rabenhorst, Krypt. Fl. 1(4): 268).
Mycelium fine, often arachnoid, branched, coenocytic at first. Colony white, often zonate and/or producing a garliclike odor. Sporangia one- to many-spored, with a rudimentary columella, which is septumlike or slightly bulged or dome-shaped. Smooth or rough chlamydospores often formed. Zygospores smooth or dimpled; suspensors apposed, unequal, naked or with a hyphal envelope.
Type genus: Mortierella Coemans.
Updated Jan 15, 2005