Key to the species of Phylloporia reported in tropical Africa

1 Basidiomes (laterally) stipitate; emerging from underground roots of (small) trees or bushes................................................ 2

1 Basidiomes sessile, emerging from aboveground organs (surfacing roots, trunks, branches, twigs, petioles, or leaves) of small trees, bushes, or liana ................................................................................................................................................ 4

2 Pileus surface with silvery concentric lines; context with a black line; pores 10–11 / mm; basidiospores ellipsoid 3.4–4.0 × 2.2–2.7 µm..................................................................................................................................... P. afrospathulata Known from the Guineo-Congolian phytochorion in Gabon. Description in Yombiyeni et al. (2015). Phylloporia spathulata, identified in literature from Central Africa (e.g., Cameroon) as are keyed out here.

2 Pileus surface homogeneously coloured; context with or without black line; pores 6–9 / mm ................................................ 3

3 Context without black line; stipe thinning toward the pileus, down 1 mm diam., bulbous at the base; pores 7–9 / mm; basidiospores mostly 2.0–3.0 × 2.5 µm .................................................................................. P. minutispora Known from the Eastern side of the Guineo-Congolian phytochorion, at medium elevation forest of the Albertine rift, Democratic Republic of Congo and Uganda. Description in Ipulet & Ryvarden (2005).

3 Context with a black line; stipe stout all over, up to 1 cm thick; pores 6–8 / mm; basidiospores mostly 2.7–3.8 × 2.0–2.9 μm, av. 3.2 × 2.4 µm ............................................................................................................................................... P. mutabilis Known from Benin, in dry forest. Description in Olou et al. (2023).

4 Basidiomes emerging from the abaxial side of living leaves; circular, button-shaped, shortly pendant, centrally attached................................................................................................................................................... P. parasitica This species in tropical Africa should be considered as sensu auctores. It is reported in tropical East Africa (Tanzania) by Ryvarden & Johansen (1980). Description in Ryvarden & Johansen (1980).

4 Basidiomes emerging from trunks, branches, twigs, petioles; distinctly pileate ...................................................................... 5

5 Pileus with a tomentum thicker than the underlying context .................................................................................................... 6

5 Pileus without tomentum, smooth or with a trichoderm much thinner than the underlying context ........................................11

6 Black line absent between the context and the tomentum ...................................................................................................... 7

6 Black line present between the context and the tomentum ..................................................................................................... 8

7 Pileus pale brown, cork-coloured; pores surface cork-coloured; pores 3–5 / mm ................................................... P. littoralis Known from an open, coastal forest in Gabon, on Nichallea sp. ( Rubiaceae), and from Benin (unidentified host). Description in Yombiyeni & Decock (2017).

7 Pileus golden yellow to rusty brown; pores surface cinnamon to rusty brown; pores 2–4 / mm......... P. fruticum sensu auct. Specimens from tropical Africa identified as P. fruticum (Ryvarden & Johansen 1980, Ryvarden et al. 2022) should be taken as sensu auctores and not sensu stricto. Description in Ryvarden et al. (2022).

8 Pores 5–6 / mm; hyphal system monomitic; basidiomes 3–10 cm wide P. weberiana sensu Ryvarden & Johansen (1980) . This species is reported in tropical Africa by Ryvarden & Johansen (1980), but it should be considered as sensu auctores. Description in Ryvarden & Johansen (1980).

8 Pores 9–11 / mm; hyphal system dimitic ................................................................................................................................. 9

9 Basidiomes 2–8 cm wide; on trunk and branches of Rawsonia lucida .................................................... P. pseudoweberiana Known from Kakamega Forest, on Rawsonia lucida ( Achariaceae), Kenya. Description above

9 Basidiomes up to 2 cm wide .................................................................................................................................................. 10

10 Basidiospores 4.0–4.5 × 2.5–3.0 μm, av. = 4.3 × 2.7 μm; pores 9–10 / mm, 85–100 µm wide; on twigs of Rinorea sp. ( Violaceae) ......................................................................................................................... P. rinoreae Known from Lower Guinean rainforest in Gabon. Description in Jerusalem et al. (2019).

10 Basidiospores 3.6–4.0 × 2.2–2.5 μm, av. = 3.9 × 2.3; 8–9 / mm, 85–124(–130) µm wide; unidentified angiosperm................................................................................................................................... P. cinnamomea Known from an unidentified angiosperm tree in Cameroon and Gabon, Guineo-Congolian rainforest. Description above.

11 Pileus with a trichoderm lying over a thin black line; hyphal system dimitic / pseudodimitic ................................................. 12

11 Pileus without trichoderm; context without black line; hyphal system monomitic .................................................................. 17

12 Basidiomes wider than 2 cm, solitary to pectinate................................................................................................................. 13

12 Basidiomes smaller, up to 2 cm wide, solitary, but emerging in large numbers..................................................................... 14

13 Basidiomes medium to large-sized,> 3 cm long, up to 25 cm wide; basidiospores 3.8–4.3 (–4.5) × 3.0–3.5 μm, av. = 4.0 × 3.2 µm, on Turraea cf. holstii ( Meliaceae ................................................................................................ P. afropectinata Known from Elgon Mountain, from roots, trunk or branches. Description above. Phylloporia pectinata sensu Ryvarden & Johansen (1980) or Ryvarden et al. (2022) are keyed out here.

13 Basidiomes up to 3 cm long, 5 cm wide, 1 cm thick; basidiospores 3.3–4.3 × 2.4–3.3 μm, av. 3.8 × 2.8 μm; on Trichilia emetica ( Meliaceae) .......................................................................................................................... P. beninensis Known from Benin in West Africa. Description in Olou et al. (2021).

14 Pileus black, finely, densely sulcate; basidiomes emerging from small branches of bushy tree; Zambezian phytochorion (Miombo); basidiospores ellipsoid, oblong ellipsoid .................................................................. P. miomboensis Known from an unidentified bushy tree in Zimbabwe. Description above.

14 Pileus greyish orange, light to dark brown, blackish; basidiomes emerging mostly from trunk; understorey of the Guineo-Congolian rainforest; basidiospores ellipsoid to broadly ellipsoid............................................................................. 15

15 Pileus greyish orange, light brown; basidiomes pendant, flabelliform, conical, thin ...................................................... P. fulva Known from the very humid rainforest at Mont de Crystal, in Gabon; host unknown; description in Yombiyeni et al. (2015).

15 Pileus darker, brown to black; basidiomes semi-circular, applanate...................................................................................... 16

16 Pore surface with greenish tint; pores 11–13/ mm; on Warneckea floribunda ( Melastomataceae) ............... P. warneckeicola Known from the Lower Guinean rainforest in Gabon. Description above.

16 Pore surface dark brown; pores 10–11/ mm; on Memecylon cf. viride ( Melastomataceae .................................... P. memecyli Known from the Lower Guinean rainforest in Gabon. Description above.

17 Basidiomes solitary; pores 2–3 / mm; basidiospores oblong ellipsoid, 4.5–5.5 × 2.0–2.5 μm .......................... P. inonotoides Known from Lower Guinean rainforest in Gabon on trunks of Crotonogyne manniana ( Euphorbiaceae). Description in Yombiyeni et al. (2015).

17 Basidiomes gregarious (10–100); pores 5–6 / mm; basidiospores on average <4 μm long................................................. 18

18 Basidiomes emerging from a common base; basidiospores narrowly ellipsoid to oblong; open (Zambezian) woodland ............................................................................................................................................................ P. microspora Known from Zimbabwe, on the trunk of Colophospermum mopane ( Fabaceae). Description above.

18 Basidiomes emerging individually; basidiospores broadly ellipsoid; Lower Guinean rainforest ............................................ 19

19 Basidiomes> 1.5 thick; pileus dull; margin irregular, incised ............................................................................. P. gabonensis Known from Euphorbiaceae in the humid Lower Guinean rainforest in Gabon. Description in Decock et al. (2015).

19 Basidiomes ≤ 1.5 mm thick; pileus shining; margin regular, entire.................................................................. P. flabelliformis Known from Euphorbiaceae in the humid Lower Guinean rainforest in Gabon. Description in Decock et al. (2015).