Tricholoma luteomaculosum A. H. Smith (1942: 67)

Ovrebo, Clark L., Hughes, Karen W. & Halling, Roy E., 2019, Three new species of Tricholoma from Costa Rica, Phytotaxa 392 (1), pp. 33-44 : 42

Tricholoma luteomaculosum A. H. Smith (1942: 67) ( Figs. 1 , 2 )

Tricholoma luteomaculosum was described from southern Michigan, and Ovrebo (1986) provided an updated description of the species especially emphasizing microscopic features and stated that it was only known from southern Michigan. Shanks (1997) also reported it from California and there are additional unverified collections from the United States and Canada that are listed on MyCoPortal. Here we officially report two collections, CLO 4632 and CLO 4623 that are morphologically T. luteomaculosum from the Great Smoky Mountain National Park (GSMNP) and hypothesize that this entity is the same as the taxon described by Smith. These collections have ITS sequences that are genetically distinct from the western U.S. fungus that is identified as T. luteomaculosum in GenBank submissions and documented by Shanks (1997). Tricholoma luteomaculosum is one of the few species of Tricholoma to possess pleurocystidia which are easy to confirm. We include it in a phylogeny to show its relationship to related taxa and report it from Great Smoky Mountains National Park.

Figures

FIGURE 1. PhyML analysis of the nuclear ribosomal ITS region. Collection locations where known are given by the US Postal code for states. GSM=Great Smoky Mountains NationalPark,Tennessee side; BC=Canada British Columbia; CR=Costa Rica; ENV=environmental sequence. Ecto=ectomycorrhizal root tip. Bootstrap values are given to the left of the supported node. Percent divergence calculations were calculated using all base pair differences (i.e., a 13bp insertion in CLO3549 and AGF21 was counted as 13 bp differences, not a single difference).

FIGURE 2. PhyML analysis of the nuclear ribosomal ITS region. Bootstrap values are given to the left of the supported node.