Acaulospora viridis, a new species in the Glomeromycetes from two mountain ranges in Andalucia (Spain)

A new Acaulospora species was found in two adjacent mountains ranges in Andalucia (southern Spain), i.e. in Sierra Nevada National Park at 1270-3200 m asl around roots of Artemisia umbelliformis, Sorbus hybrida, Laserpitium longiradium among others, and in a shrubland and grassland at 1855-2028 m asl in the Sierra de Baza Natural Park. The fungus produced spores in single species cultures, using Sorghum vulgare or Trifolium pratense as bait plant. The new species was named A. viridis because of its greenish appearance under the dissecting and in the compound microscope. The spores have a smooth surface and are similar in size to several other Acaulospora species, such as A. koskei, A. laevis, A. capsicula, A. colliculosa and A. entreriana. However, the new species can easily be distinguished from all these fungi by the diagnostic staining of the middle wall in Melzer's reagent. Phylogenetic analyses of sequences obtained from the ITS and partial LSU of the ribosomal genes confirm the new species in a clearly separate clade within the Acaulosporaceae.