Rubroboletus, Kuan Zhao et Zhu L. Yang, 2014

Zhao, Kuan, Wu, Gang & Yang, Zhu L., 2014, A new genus, Rubroboletus, to accommodate Boletus sinicus and its allies, Phytotaxa 188 (2), pp. 61-77 : 72

Key to the species of Rubroboletus

1 Pileus shiny when dry and strongly viscid when wet; pileal surface turning dark blue when bruised .............................................2

1 Pileus not shiny when dry, only slightly viscid when wet; pileal surface turning dark red or unchanging when bruised ................3

2 Pileal surface scarlet to tinged ochraceous when mature; surface of the hymenophore blood red to dark red when mature; context pale yellow; in Europe, also reported from North and Central America ........................................................................... R. dupainii

2 Pileal surface blood red to dark red when mature; surface of the hymenophore orange red when mature; context whitish to cream-colored; in East Asia............................................................................................................................................ R. latisporus

3 Pileal surface glabrous; spores subfusiform, with a conspicuous suprahilar depression; in North and Central America and Europe ............................................................................................................................................................................................................4

3 Pileal surface felty-tomentose; spores ovoid-ellipsoid, with an inconspicuous suprahilar depression; in East Asia.......... R. sinicus

4 Context yellowish to pale yellow when mature; stipe club-shaped or sub-cylindrical .....................................................................5

4 Context whitish to white when mature; stipe usually strongly bulbously swollen at the base .......................................... R. satanas

5 Both the context of the cap and the stipe becoming blue when injured ............................................................................................6

5 Context of the cap becoming blue but that of the stipe unchanging when injured .................................................. R. rhodoxanthus

6 Pileal surface unchanging when bruised; odor of hey or not distinct; taste slightly acid .................................................................7

6 Pileal surface turning dark red when bruised; odor of overripe fruit; taste sweet ............................................... R. rhodosanguineus

7 Stipe covered with red to dark red reticula; odor of hey; in coniferous forests, such as Picea spp. and Abies spp. ........................... .............................................................................................................................................................................. R. rubrosanguineus

7 Stipe covered with pink reticula; odor not distinct; in broad-leaved forests, such as Quercus spp. ........................ R. pulchrotinctus