UMBELOPSIS Amos & H.L. Barnett, 1966 (Mycologia 58: 807); 13 spp. (Amos and Barnett 1966; von Arx 1982 ; Yip 1986a, 1986b; Meyer and Gams 2003; Sugiyama et al. 2003; Mahoney et al. 2004).
= Micromucor (W. Gams) von Arx, 1982  (Sydowia 35: 19) non Micromucor Malchevskaya, 1939.
Sporangiophores arising from a vesicle on the stipe, borne cymosely or verticellately, terminating in uni- or multispored, ochraceous to reddish sporangium that may or may not have a columella. Sporangiospores angular or not angular and variously shaped, the same color as the sporangia; appendaged in some species. Chlamydospores often abundant. Zygospores unknown.
Type species: U. versiformis
Species of Umbelopsis:
U. angularis W. Gams & M. Sugiyama, 2003 (Mycoscience 44: 221).
U. autotrophica (E.H. Evans) W. Gams, 2003 (in Meyer and Gams, Mycol. Res. 107: 349).
U. dimorpha Mahoney & W. Gams, 2004 (in Mahoney, Gams, Meyer and Starink-Willemse, Mycol. Res. 108: 109).
U. fusiformis Yip, 1986 (Trans. Brit. Mycol. Soc. 86: 334).
U. gibberispora M. Sugiyama, Tokumasu & W. Gams, 2003 (Mycoscience 44: 220).
U. isabellina (Oudemans) W. Gams, 2003 (in Meyer and Gams, Mycol. Res. 107: 349).
U. nana (Linnemann) von Arx, 1982  (Sydowia 35: 20).
U. ovata Yip, 1986 (Trans. Brit. Mycol. Soc. 86: 334).
U. ramanniana (A. Möller) W. Gams, 2003 (in Meyer and Gams, Mycol. Res. 107: 349).
U. swartii Yip, 1986 (Trans. Brit. Mycol. Soc. 87: 243).
U. versiformis Amos & H.L. Barnett, 1966 (Mycologia 58: 807).
U. vinacea (Dixon-Stewart) von Arx, 1982  (Sydowia 35: 20).
U. westeae Yip, 1986 (Trans. Brit. Mycol. Soc. 87: 245).
Umbelopsis is a genus originally described as deuteromycete (Amos and Barnett, 1966) and the genus was later treated as a zygomycete related to either the Mucoraceae or Thamnidiaceae (Mucorales) (von Arx, 1982). Umbelopsis includes many species that were originally described as species of Micromucor or that were transferred to the latter genus from Mortierella or even Mucor.
Members of Micromucor and Umbelopsis were distinguished morphologically because of differences in sporangiophore branching and columella formation; Umbelopsis also has a few species with unispored sporangia (von Arx, 1982). Yip (1986a) said that the main reason for separating these two genera, sporangiophore length and branching cannot be used to separate Micromucor and Umbelopsis because short and long sporangiophores have been reported in M. isabellina (Turner, 1963). Yip (1986a) then suggested that all species of Micromucor should be transferred to Umbelopsis. This has been substantiated because some species of Umbelopsis can be highly variable morphologically (Kendrick et al., 1994; Ogawa et al. 2005).
Meyer and Gams (2003), using RFLP of the ITS region and ITS1 sequence comparison, reveal that the two sister clades in the Mortierella isabellina group did not correspond with spore pigmentation or any morphological character and, therefore, all of these fungi are being treated as members of Umbelopsis. One species, Mortierella longicollis, which is morphologically similar to members of Umbelopsis, may be a member of Mortierella and not Umbelopsis according to Meyer and Gams (2003).
Several species were originally described in Umbelopsis by Yip (1986a, 1986b), Sugiyama et al. 2003) and Mahoney et al (2004). Other taxa were transferred to Umbelopsis from Micromucor (Yip, 1982, 1986a; von Arx 1982 ; Meyer and Gams 2003). Two species of Umbelopsis [U. roseonana (W. Gams & Gleason) von Arx, Umbelopsis multispora T. Watanabe] are considered synonyms of other members of the genus (von Arx 1982 ; Watanabe 1977).
Amos, R.E., Jr., and H.L. Barnett. 1966. Umbelopsis versiformis, a new genus and species of the imperfects. Mycologia 58:805-808.
Kendrick, B., J.E. Smith, J. Neville, and N.S. Weber. 1994. A study of morphological variability, character analysis, and taxonomic significance in the zygomycetous anamorph-genus Umbelopsis. Mycotaxon 51:15-26.
Mahoney, D., W. Gams, W. Meyer, and M. Starink-Willemse. 2004. Umbelopsis dimorpha sp. nov., a link between U. vinacea and U. versiformis. Mycological Research 108:107-111.
Meyer, W., and W. Gams. 2003. Delimitation of Umbelopsis (Mucorales, Umbelopsidaceae fam. nov.) based on ITS sequence and RFLP data. Mycological Research 107:339-350.
Ogawa, Y., A. Suda, K. Kusama-Eguchi, K. Watanabe, and S. Tokumasu. 2005. Intraspecific groups of Umbelopsis ramanniana inferred from nucleotide sequences of nuclear rDNA internal transcribed spacer regions and sporangiospore morphology. Mycoscience 46:343-351.
Sugiyama, M., S. Tokumasu, and W. Gams. 2003. Umbelopsis gibberispora sp. nov. from Japanese leaf litter and a clarification of Micromucor ramannianus var. angulisporus. Mycoscience 44:217-226.
Turner, M. 1963. Studies in the genus Mortierella I. Mortierella isabellina and related species. Transactions of the British Mycological Society 46:262-272.
Von Arx, J.A. 1982 . On Mucoraceae s. str. and other families of the Mucorales. Sydowia 35:10-26.
Watanabe, T. 1977. A new species of Umbelopsis from strawberry roots. Transactions of the Mycological Society of Japan 18:242-244.
Yip, H.Y. 1982. Mortierella ovata sp. nov. Transactions of the British Mycological Society 79:162-165.
Yip, H.-Y. 1986a. Umbelopsis fusiformis sp. nov. from a wet sclerophyll forest and a new combination for Mortierella ovata. Transactions of the British Mycological Society 86: 334-337.
Yip, H.-Y. 1986b. Two new species of Umbelopsis from soil in Australia. Transactions of the British Mycological Society 87: 243-248.
Updated May 05, 2010