Specimens examined: Holotype: 11474, on Brachyglottis repanda J. R. et G. Forst., May 1952, G. H. Cunningham, Hicks Bay, Aukland, New Zealand, in herb. PDD. USA: LOUISIANA - RLG 13549, on Ulmus rubra Muhl., Baton Rouge Parish (ARIZ, CFMR).

Basidiocarp broadly effuse, up to 15 x 2.5 cm in extent, up to 150 µm thick, membranous, tightly adherent; fertile area continuous, smooth, not cracked, "yellowish white" (3A2) to "dull yellow" (3B4); margin up to 0.25 mm wide, thinning out, fibrillose, irregular in outline, white. Hyphal system monomitic. Subiculum a textura intricata, hyphae 3.5-5.5 µm diam, thin walled or firm walled, hyaline, long celled, simple septate, smooth; subhymenium a compact textura intricata porrecta, hyphae 2.5-3.5 µm diam, thin walled, hyaline, short celled, simple septate; cystidia lacking; basidia clavate with slight median constriction, (27-)35-40 x 6.5-8.5 µm, thin walled, hyaline, 4-sterigmate, sterigmata up to 5 um long; basidiospores narrowly ellipsoid, (7-)8-9.5 x 3.5-4.5 µm, hyaline, thin walled, smooth, Melzer's -, acyanophilous.

Known only from New Zealand and Louisiana.

On hardwood branches; associated with a white rot.

Discussion: Phanerochaete corymbata is similar to P. auratum, P. tuberculata, and P. xerophila. It differs from P. auratum that has hyphae more than 6 µm wide and wider spores 7.5-9 x 4.5-5.5(-6) µm. Phanerochaete tuberculata has a fibrillose to nearly cordonic basidiocarp, some nodose septate hyphae, and basidiospores 6-7.5 x 3.5-4.5 µm. Phanerochaete xerophila has basidiospores 6-8 x 3.5-4.5 µm giving them a more broadly ellipsoid shape than in P. corymbata.
This species has been collected recently in Louisiana, the first time since its original collection. This results in an unusual distribution for this poorly known species. The second specimen differs from the type only in possessing a highly cracked fruiting body and hyphae encrusted with hyaline crystals.

Holotype: 17455, on unknown woody substrate, 1914, Manaku Forest, Auckland, New Zealand, W. N. Cheeseman, in herb. K; isotype in herb. PDD.

Basidiocarps adherent, broadly effused, membranous to ceraceous, smooth, up to 1 mm thick; fertile area "greyish orange" (near 5B4), not changing color in KOH; margin abrupt, not differentiated; subiculum pale yellow, very thin, often not observable. Hyphal system monomitic. Subiculum sparse, not evident in many sections, hyphae 4-6.5 µm diam, thin walled to firm walled, yellow, with regular branching at right angles, smooth or coated with orange granules that frequently dissolve in KOH turning solution yellow, simple septate; subhymenium making up most of thickness, with hymenial elements imbedded at all levels, hyphae 3-4.5 µm diam, hyaline, thin walled; cystidia of two kinds, some subulate and mostly smooth or only lightly covered with orange granules, with most granules dissolving in KOH; some heavily encrusted and cylindrical, 35-65 x 4-6 µm (-9 µm when heavily encrusted), thin walled or with only slight thickening, with rare secondary septa, embedded at all levels, the embedded ones with orange crystals, persistent even in KOH; basidia cylindrical, 40-50 x 5-6 µm, thin walled, hyaline, 4-sterigmate, sterigmata up to 3.5 Itm long; basidiospores ellipsoid to narrowly ellipsoid, 5-5.5 x 2.5-3 µm, hyaline, smooth, thin walled, Melzer's -, acyanophilous.

New Zealand, known only from type collection.

On bark of dead branches.

Discussion: The only Phanerochaete species with which P. luteo-aurantiaca could be confused is P. ericina. Phanerochaete luteo-aurantiaca is distinguished by cystidia encrusted with orange crystals or granules and by the absence of the much branched binding-type hyphae present in P. ericina.