Phanerina mellea (Berk. & Broome) Miettinen

Miettinen, Otto, Spirin, Viacheslav, Vlasak, Josef, Rivoire, Bernard, Stenroos, Soili & Hibbett, David S., 2016, Polypores and genus concepts in Phanerochaetaceae (Polyporales, Basidiomycota), MycoKeys 17, pp. 1-46 : 16-18

Phanerina mellea (Berk. & Broome) Miettinen comb. nov. Figures 1band 8

Polyporus melleus Berk. & Broome, J. Linn. Soc., Bot. 14: 53 (1873).

Description.

Basidiocarp resupinate, yellow, ranging from yellowish cream to brownish yellow, 1 –10×1– 5 cm patches, 1(2) mm thick. Consistency fragile when dry. Pores shallow, somewhat irregular, splitting and eventually may turn dentate, 2-4 per mm, larger when split. Subiculum cream-colored, a bit lighter than pore surface, pellicular, cottony under the lens, 0.1-0.3 mm. Margin thinning out, smooth areas of several millimeters similar to tube bottoms may be present.

Hyphal system monomitic, clamps absent. Hyphae cylindrical, not much swollen, branching in sharp angles, rather similar throughout the basidiocarp, CB− to CB(+), IKI−, KOH−, CRB lilac. Large crystal clumps mostly of rhomboidal shape present in trama. Subiculum loose, hyphae interwoven, slightly thick-walled to thick-walled when old, (2)3-5(6.4) µm in diameter, walls mostly <0.5 µm thick, up to 1.2 µm in old basidiocarps. Tramal hyphae subparallel, thin- to slightly thick-walled, (2)3-3.8(4.8) µm in diameter. Subhymenium branching corymb-like, cells not sinuous, relatively easy to study.

Cystidia present but often rare, hymenial, thin-walled, subulate, rarely septate, naked, 40 –80×5.8– 9.2 µm, projecting 20-50 µm.

Hymenium relatively loose. Basidia clavate, 15 –26×5.2– 6.8 µm, with 4 wide, spindle-shaped sterigmata, 4 –4.8× 1.8 µm.

Basidiospores cylindrical to narrowly ellipsoid, usually abundant, with thin but distinct walls, smooth, (5.2)5.8 –7.5(7.8)×(2.8)2.9– 3.8(4.4) µm, L=6.55 µm, W=3.26 µm, Q’ = (1.6)1.8-2.3(2.4), Q=2.01. Spore shape variation is rather large and abnormally broad ellipsoid spores can be present.

Distribution.

Described from Sri Lanka. We can confirm it from East Africa (Tanzania, Kenya), Japan (Okinawa), and Indonesia (New Guinea). Sequences of Chinese specimens are also available in the INSDC.

Ecology.

Grows on dead dicot trees, both standing and fallen, often in sun-exposed habitats.

Remarks.

East Asian, East African and New Guinean specimens have neither ITS sequence differences nor morphological differences, so we feel it is safe to assume that the type from Sri Lanka belongs to the same species. Morphologically the type specimen agrees very well with other material. Its spores are a little larger on average than in other specimens studied, but considering the large variability in size and shape of spores this is best interpreted as normal variance within species.