Ionosporus: a new genus for Boletus longipes and a new species, I. australis from Australia

From: Khmelnitsky et al. 2019. Mycological Progress 18: 439–451.


Background: Boletus longipes was described  by George Massee (1909) from a specimen collected in Singapore. Modern placement in subg. Tylopilus (Corner 1972), Porphyrellus (Wolfe & Petersen (1978) or in Austroboletus (Wolfe 1979) is not supported based on morphological and molecular data. Additional field work in Australia revealed an additional species previously undescribed: I. australis.

Spore ornamentation (irregularly and finely pitted to granulose) and a purple-violet color reaction in dilute KOH solution are traits similar to Borofutus, Rhodactina, Spongiforma (subfam. Leccinoideae).

Molecular phylogenetic inference provides a new perspective on placement of I. longipes and I. australis in subfam. Leccinoideae in the Boletaceae. The partial phylogram is based on a rpb2 dataset (engineered by O. Khmelnitsky). The tree topology corresponds to the optimal maximum likelihood tree calculated by RAxML. Support values > 50% bootstrap and 0.5 posterior probability are shown.