Racocetra Oehl, F.A. Souza & Sieverd.
| Term | Description |
|---|---|
| Etymology: | Greek, races = “cloth, lobes” and Latin, cetra = “light shield” |
| Description: | Spores with or without ornamentations. Spores consist of a bilayered spore wall and one bilayered flexible inner germinal. Germ tubes arise from a persistant, plate-like germination shield that is always associated with the germinal wall. Thin-walled auxiliary cells with smooth to knobby surfaces, are produced on hyphae in the soil near the root surface. |
| Type species: | basionym = S. coralloidea Trappe, Gerd. & I. Ho |
Spore Development
Spore development is like that depicted for Scutellospora, except that only a single germinal wall with two thin hyaline layers is formed. Discounting R. weresubiae as a fluke (for whatever reason you are able to conjure), this is the only genus where morphological and rRNA gene evolution are congruent (Oehl et al., 2008; Redecker et al., 2013). Because of such strong congruence, evolution in this clade is likely to hold up as other evidence is obtained (Morton and Msiska, 2010). The other clades, maybe not so much.
Literature Cited
- Morton, J. B. and Z. Msiska. 2010. Genetic and morphological characters do not support revised ranking of Scutellospora species (Gigasporaceae, Glomeromycota) into three families and four genera. Mycorrhiza 20:483-496.
- Oehl, F., F.A. de Souza and E. Sieverding. 2008. Revision of Scutellospora and description of five new genera and three new families in the arbuscular mycorrhiza-forming Glomeromycetes. Mycotaxon 106:311-360.
- Redecker, D., A. Schüßler, H. Stockinger, S. Stürmer, J. Morton, and C. Walker. 2013. An evidence-based consensus for the classification of arbuscular mycorrhizal fungi (Glomeromycota). Mycorrhiza doi:10.1007/s00572-013-0486-y.