Amanita species within section Caesareae from the highlands of Laos

Specimens of Amanita sect. Caesareae, collected in Xieng Khouang and Vientiane provinces in Laos from highland forests dominated by members of Fagaceae and Pinaceae, are studied based on morphological characters and analyses of ITS sequences. Two species, namely A. princepoides and A. chepangianoides, are reported as new, both found in association with Fagaceae, whereas A. pseudoprinceps and A. subhemibapha, recently described from China and A. rubromarginata from Japan, are confirmed from Laos and found in forests with Fagaceae and Pinaceae. The phylogenetic analyses to recognize the Amanita species showed that the golden-brown to greyish orange A. princepoides and the dominantly white A. chepangianoides cluster with A. aporema, A. chepangiana, A. egregia, A. princeps and A. pseudoprinceps. A dichotomous key to identified and likely occurring Amanita species in Laos within sect. Caesareae is also provided.