Rubroboletus eastwoodiae (Murrill) Vasquez, Simonini, Svetasheva, Mikšík & Vizzini
Index Fungorum number: IF552780; Facesoffungi number: FoF 2813
Basionym: Suillellus eastwoodiae Murrill, N. Amer. Fl. (New York) 9 (3): 152 (1910)
It is worth noting that the combination R. eastwoodiae (Murrill) Arora, C.F. Schwarz & J.L. Frank (Frank 2015) is invalid (wrong citation of the basionym). Curiously, R. demonensis shares both the growth area and edaphic-environmental conditions of another Mediterranean species very common in Sicily and Calabria, Boletus flavosanguineus Lavorato & Simonini: frequently these boletes are observed growing together (pers. obs.).
The analysis of the spore size distribution with the method of the “isoprobability ellipses” (Simonini 1992, 1998; Consiglio and Simonini 2005) is based on average values of 20 collections of R. rubrosanguineus, 13 collections of R. legaliae, and 7 collections of R. demonensis. This comparison allows to analyse better the differences of the spores both in size and shape. It could be observed that spores of R. demonensis and R. legaliae are clearly separated each other even at confidence level of 95%, having R. demonensis clearly shorter and narrower spores. R. rubrosanguineus has some overlapping with the other species only at confidence level of 95%, while at 68% there is almost no overlapping: R. demonensis has narrower and stouter spores with respect to R. rubrosanguineus, and the latter has slender and longer spores with respect to R. legaliae. The difference in width of the spores of R. rubrosanguineus and R. legaliae is statistically not significant.
Distribution of spore size of R. demonensis (7 collections), compared with R. legaliae (13 collections) and R. rubrosanguineus (20 collections), using “isoprobability ellipses”. It is shown the distribution of the average values of spore size for any of the collections, at the confidence of 68% (corresponding to 1st deviation, left side) and at the confidence of 95% (correspondent to 2 × st. deviation, right side).