Specimen examined: New Zealand, Otago Distr., 30 Mar. 1966, McNabb, PDD 25175, K, isotype.

Spores 7-9 x 4.2-6 (7.8 ± 0.7 x 5.2 ± 0.5) µm; Q = 1.50, ovo-ellipsoid with suprahilar applanation, melleous, surface finely rugulose.

Chalciporus has been hitherto restricted (Singer, 1975) to a few Northern Tempertae boletes but there exist in the intertropical regions, especially in equatorial Africa and the Caribbean area, a number of species with similar characteristics. Additional species also occur in Australasia. These have in common a gymnocarpic basidiome with an ixotrichodermial pileipellis, a broadly adnate to decurrent reddish hymenophore, a slender tapering stipe with a bright yellow basal mycelium, and a snuff-brown to cinnammon brown spore deposit which lacks any olivaceous tints.
The hymenophore frequently shows a radial, boletinoid arrangement which, together with the viscid pileus, has lead to confusion with the genus Suillus. Chalciporus, however, never has fasciculate cystidia, nor does it neccessarily form obligate mycorrhizal associations with conifers. In many species, associations are formed with trees of the Fagales and Salicales, and some of the tropical species are probably not mycorrhizal. They might, therefore, be considered at an equivalent phyletic level of development with Pulveroboleus (Boletaceae) and Xerocomus (Xerocomaceae), and they show a similar range of variation both in he degree of gelatinization of the hymenophoral trama and pileipellis, and in spore form.
The reddish, often decurrent hymenophore, the slender tapering stipe and yellow mycelium could indicate a common ancestry with the Gomphidiaceae.