Coltricia laeta (Cooke) G.H. Cunn. is closely related to C. aureofulva with similar fruit-body colour, red colour of hyphae in KOH, and similar spores. It differs in its larger and more robust form, larger pores, and wider, thinner-walled, more frequently simple septate hyphae. As with C. aureofulva, we consider that this species belongs in Rigidoporus, as: Rigidoporus laeteus (Cooke) P.K. Buchanan & Ryvarden comb. nov. Basionym: Polyporus laetus Cooke, Grevillea 12: 16 (1883).

Type: Lignicolous Fungi; Description: Basidiomata annual, solitary or with overlapping pilei, leathery becoming woody, attached by a narrow lateral base. Pilei fan-shaped, sometimes applanate, 30–60 mm wide, 5–10 mm thick. Pileus surface glabrous, radiately striate, reddish orange to orange-brown, margin usually entire, sometimes fluted or lobed, concolorous. Pore surface even, reddish orange, darkening with age to deep brick red; pores minute, 9–10 per mm. Context reddish orange, shining, 2–5 mm thick. Hyphal system monomitic. Basidiospores globose, 4–6 μm in diameter, smooth, hyaline.

Distribution: Auckland, Coromandel, Waikato, Wellington, Gisborne, Fiordland.; 1st Record: Cunningham (1948c: as Coltricia laeta).

Significance: Of no significance. Causes a white-pocket heart rot with orange zone lines.; Host(s): Elaeocarpus dentatus, Nothofagus menziesii.