Heimioporus species (16 names listed in the Digest) are primarily confined to eastern Asia (Japan and China), Indo-malaya to eastern Australia (so far) and Tasmania (13 names, 11 taxa). The remaining 3 are only known from the Americas (H. alveolatus, H. betula, H. ivoryi). Horak (2005) provided the necessary nomenclatural updates from Heimiella to Heimioporus in a list of taxa. He recognized two subgenera based on spore morphology:

subg. Heimioporus — spore surface alveolate reticulate

subg. Punctisporus — spore surface pitted

Heimioporus alveolatus from Mexico (Heim & Perreau, 1964) is virtually identical, both macro- and microscopically, to H. betula and is undoubtedly a later synonym. Unfortunately, alveolatus was only known from the type specimen (Natural History Museum of Paris), and is apparently no longer extant.

Likewise, H. anguiformis, described by R. Heim (1963) from Papua New Guinea, appears to be known only from the type specimen (Paris) and is also apparently no longer extant. However, published photomicrographs of spores and an exquisite color plate of the macroscopic appearance of the species leave little doubt as to its uniqueness (Heim 1965).

While spore color has been used traditionally as a distinguishing character for bolete genera, the definitiveness of this feature appears not as rock-solid as previously thought (Xanthoconium 'austroseparans' in ed.). However, the olive brown spores of Heimioporus will readily distinguish the few punctate-spored taxa from those of Austroboletus (vinaceous pinkish to pinkish flesh colored spores) with generally similar ornamention. Punctate or alveolate-reticulate spores do not occur in Boletellus, and this latter genus appears distinct from Heimioporus as inferred from gene sequence data.

Key to Known Species

1. Pileus some shade of red (crimson, scarlet, rhubarb, etc.)
retisporus, ivoryi, mandarinus, betula, fruticicola, japonicus, rubropunctus, xerampelinus

2. Japan (NE Asia) to Australia
retisporus, mandarinus, japonicus, rubropunctus, fruticicola, xerampelinus, also possibly betula

3. Pileus conic-umbonate, alveolate [mandarinus, rubropunctus]

4. Spores alveolate-reticulate - - - H. mandarinus

4. Spores with large, circular or elongated pits - - - H. rubropunctus

3. Pileus convex [retisporus, japonicus, fruticicola, xerampelinus]

5. Spores ellipsoid or rarely subglobose - - - H. retisporus

5. Spores fusoid, subfusoid to elongate-ellipsoid [japonicus, fruticicola, xerampelinus]

6. Spore surface finely rugulose with crater-like ornamentation - - - H. fruticicola

6. Spores alveolate-reticulate [japonicus, xerampelinus] N.B. The latter taxon is a later synonym of the former.

2. America [ivoryi, betula]

7. Spores alveolate-reticulate - - - H. ivoryi

7. Spores punctate - - - H. betula

1. Pileus never red (brown, fawn, pale tan to ochraceous or black) [anguiformis, kinabaluensis, subretisporus, nigricans, punctisporus.]

8.Pileus surface cerebriform; stipe apex pinkish orange - - - H. anguiformis

8. Pileus surface even to somewhat rugulose to shallowly subalveolate, but NOT cerebriform; stipe apex some other color [kinabaluensis, subretisporus, nigricans, punctisporus.]

9. Spores punctate - - - H. punctisporus

9. Spores reticulate, not punctate

10. Pileus black - - - H. nigricans

10. Pileus brown to bright fawn

11. Pileus even - - - H. subretisporus

11. Pileus rugulose - - - H. kinabaluensis

Heim, R. 1963. Diagnoses latines des espèces de Champignons, ou nonda, associé à la folie du komugl taï et du nadaadl. Rev. Mycol. (Paris) 28: 277-283.

Heim, R. 1965. Les champignons associés a la folie de kuma: étude descriptive et iconographie. Cahiers du Pacifique 7: 7-65.

Heim, R. & J. Perreau. 1964. Les genres Porphyrellus et Strobilomyces au Mexique. Bull. Soc. Mycol. France 80: 88-101.

Horak, E. 2005. Heimioporus E. Horak gen. nov. - replacing Heimiella Boedijn (1951, syn. post., Boletales, Basidiomycota). Sydowia 56: 237-240.