ZYGORHYNCHUS Vuillemin, 1903 (Bull. Soc. Mycol. France 19:116); 9 spp. + 2 var. (Hesseltine et al., 1959; Zheng, 2002)

The sporangia of species of Zygorhynchus are globose, nonapophysate, and with a deliquescent wall. Zygospores form zygosporangia that have a brown to black, roughened wall. The suspensors are opposed and heterogamous (at maturity, one suspensor is as large, or nearly so, as the zygosporangium, and the other usually is barely, or not, visible). All known species are homothallic.

Type species: Z. heterogamous

Species of Zygorhynchus:
Z. californicus Hesseltine, C.R. Benjamin & B.S. Mehrotra, 1959 (Mycologia 51:185) .
Z. exponens Burgeff var. exponens, 1924 (Bot. Abhandl. 4:34)
Z. exponens var. smithii, Hesseltine, C.R. Benjamin & B.S. Mehrotra, 1959 (Mycologia 51:179).
Z. heterogamous (Vuillemin) Vuillemin, 1903 (Bull. Soc. Mycol. France 19:117).
Z. japonicus Kominami, 1914 (Mycolog. Centralb. 5:3).
Z. macrocarpus Ling-Young, 1930 (Rev. Gén. Bot. 42:150 [Zygospores of Z. macrocarpus were described from cultures grown below 20 C by Hesseltine and Ellis, 1961]).
Z. moelleri Vuillemin, 1903 (Bull. Soc. Mycol. France 19:117).
Z. multiplex R.-Y. Zheng, 2002 (Mycotaxon 84:370).
Z. psychrophilus Schipper & Hintikka, 1969 (Antonie van Leeuwenhoek J. Serol. Microbiol. 35:29)

Seven taxa of Zygorhynchus are recognized by Hesseltine et al. (1959). An eighth species was added by Zheng (2002). Schipper 1986) retains species of Mucor transferred to Zygorhynchus by von Arx (1982) in Mucor. Schipper et al. (1975) and O’Donnell et al. (1978) present SEM pictures of zygosporangial ornamentation. Edelmann and Klomparens (1995) studied the ontogeny of zygospore formation and suggested the standardization of structural names. Zygorhynchus is a common member of the mucoralean flora of some soils.


Edelmann, R.E., K.L. Klomparens. 1995. Zygosporogenesis in Zygorhynchus heterogamous, with a proposal for standardization of structural nomenclature. Mycologia 87:304-318.

Hesseltine, C.W., C.R. Benjamin, and B. S. Mehrotra. 1959. The genus Zygorhynchus. Mycologia 51:173-194.

O’Donnell, K.L., S.L. Flegler, J.J. Ellis, and C.W. Hesseltine. 1978. The Zygorhynchus zygosporangium and zygospore. Can. J. Bot. 56:1061-1073.

Schipper, M.A.A. 1986. Notes on Zygorhynchus species. Persoonia 13:97-105.

Schipper, M.A.A., R.A. Samson, and J.A. Stalpers. 1975. Zygospore ornamentation in the genera Mucor and Zygorhynchus. Persoonia 8:321-328.

von Arx, J.A. 1982 [1984]. On Mucoraceae s. str. and other families of the Mucorales. Sydowia 35:10-26.

Zheng, R.-Y. 2002. Zygorhynchus multiplex, a new species from paddy soil. Mycotaxon 84:367-378.

Updated Mar 12, 2005