Boletus rubricitrinus belongs in Pulchroboletus (Boletaceae).

Abstract

The boletes are macrofungi which have undergone extensive taxonomic revisions since the advent of molecular tools. This paper provides the first DNA sequences of Boletus rubricitrinus, a common Florida bolete often found in lawns under Quercus, and likely has a distribution that extends to Texas. Based on ITS and LSU sequences and morphological studies we propose moving it to the genus Pulchroboletus. As the holotype is in poor condition, an epitype is established here. A thorough description of macroscopic and microscopic features is also provided for the species. These molecular and morphological data will be useful to further improve our understanding of bolete taxonomy.

Rubinosporus auriporus gen. et sp. nov. (Boletaceae: Xerocomoideae) from Tropical Forests of Thailand, Producing Unusual Dark Ruby Spore Deposits

“…However, no sequences of Alessioporus were added in the phylogeny because among the genes that were used to infer our phylogeny, only a partial tef1 sequence of A. ichnusanus was available in GenBank. However, in ITS and combined ITS+ LSU+tef 1 phylogenies of previous studies, Alessioporus was sister to Pulchroboletus [46,54,56]. In this study, Pulchroboletus was sister to Aureoboletus with high support, and distant from Rubinosporus.…”

“…ichnusanus was available in GenBank. However, in ITS and combined ITS+ LSU+ tef 1 phylogenies of previous studies, Alessioporus was sister to Pulchroboletus [ 46 , 54 , 56 ]. In this study, Pulchroboletus was sister to Aureoboletus with high support, and distant from Rubinosporus .…”

“…Smooth basidiospores are found in Alessioporus, Pulchroboletus, most species in Aureoboletus [3,31,46,54,55], and the new genus Rubinosporus. The basidiospores of the single Rubinosporus species, R. auriporus showed a weakly dextrinoid reaction in Melzer's reagent, similar to two species in Alessioporus and Pulchroboletus, namely A. ichnusanus and P. roseoalbidus whereas the other species in the two latter genera are not dextrinoid [46,[54][55][56]. Therefore, the character cannot be considered typical for Rubinosporus.…”

“…Alessioporus is clearly different by the reticulated stipe occasionally with a granular ring-like zone in the middle or lower half of the stipe; rapidly bluing hymenophore, stipe surface, and context when bruised or exposed; sub-ellipsoid to fusiform, ellipsoid to subcylindrical basidiospores; olive brown spore deposit; and distribution in Mediterranean Italy and subtropical USA [ 54 , 55 ]. Pulchroboletus differs by the stipe surface with scattered red to reddish brown punctae, occasionally with reticulum or longitudinal striations, and with a pseudo-annulus; hymenophore and context usually intensively staining blue when bruised or cut; ellipsoidal to ellipsoid-fusoid basidiospores; olive brown colored spore deposit; so far found in Mediterranean Europe and tropical to subtropical America [ 46 , 54 , 56 ].…”

“…ichnusanus and P . roseoalbidus whereas the other species in the two latter genera are not dextrinoid [ 46 , 54 , 55 , 56 ]. Therefore, the character cannot be considered typical for Rubinosporus .…”