ADDITIONAL SPECIMENS EXAMINED: TAUPO: Kaimanawa Ranges, on Nothofagus solandri var. cliffortioides, G. H. Cunningham, Sep 1956, PDD 17324; Tongariro National Park, Waihohonu Track, on N. solandri var. cliffortioides, J. Bedford, 26 Mar 1984, PDD 50487. HAWKE'S BAY: vic. Tutira, Bellbird Scenic Reserve, on N. fusca, R. E. Beever 1851, 18 Oct 1999, PDD 71024. WELLINGTON: Butterfly Reserve, on N. fusca, G. B. Rawlings, May 1946, PDD 7088; Kaitoke Regional Park, vic. Terrace Track, on ?Nothofagus sp., H. Lepp, 7 May 1997, PDD 70619. MARLBOROUGH SOUNDS: Mt Stokes Track, near road, on fallen N. ?menziesii, P. R. Johnston, 11 May 1997, PDD 70618.

Basidiocarps annual, resupinate, effused, to 15 x 4 cm, soft and fragile when fresh; pore surface bright reddish purple (24.1.m.r P - 23.8.deep r P) when fresh, with margin variable, to 1 mm across and undifferentiated in colour in mature parts or in young specimens to 5 mm across and fading to white at edge, sometimes with greenish tinge; pore surface changing on drying to a range of colours even within a single basidiocarp, sometimes remaining reddish purple (24.5.gy.r P) in parts, also reddish orange (39.gy.r O - 37.m.r O), brownish pink (33.br Pink), and pale orange-yellow (73.p.OY), brownish orange (54.br O) in oldest herbarium specimens, no reaction with 3% KOH; hymenophore when dry varying from distinctly poroid to reticulately poroid with broadly rounded pore mouths, sometimes with irregularly arranged pits, in less mature parts pores distinguished only as very shallow depressions; pores round to angular, 3-5 per mm; tube layer up to 3 mm deep when fresh, shrinking and up to 1 mm deep when dry; subiculum soft, floccose, white, up to 1.5 mm thick when dry though mostly thinner. Hyphal system monomitic; generative hyphae with simple septa, sometimes slightly constricted at septa, hyaline, with wall thin or thickened to 0.75 µm, 2.5-5 µm diam. in subhymenium, 3-6(-7.5) µm in subiculum, moderately branched, more loosely arranged in subiculum than subhymenium, mostly smooth in subiculum, sometimes covered with variable masses of yellowish semicrystalline material in subhymenium and this same material covering cystidioles. Cystidioles present particularly at pore mouths or on edges of folds where they tend to dominate the hymenium, thin-walled, cylindrical to elongate- clavate, covered in yellowish semicrystalline material, 25-65 x 5-8 µm. Basidia cylindrical to clavate, 4-sterigmate, simple-septate at base, 14-22 x 4.5-6 µm, forming a continuous layer amongst cystidioles at the pore mouth. Basidiospores ovoid to ellipsoid, adaxially flattened, smooth and thin-walled, hyaline, IKI-, 4.3-5 x 2.5-3 µm. Causing a white rot of wood.

New Zealand, widespread on both North and South Islands although apparently uncommon.

SUBSTRATA: Recorded only on Nothofagus species.

Basidiocarpi annui, resupinati, usque 15 x 4 cm, ab ineuntes molles atque fragiles; superficies pori primo vivide rubelli-purpurea, postea in statu exsiccato diverse multicolor, poroidea, reticulatim poroidea vel foveis irregulariter dispositis praedita, 3-5 per mm; stratum tuborum in sicco usque 1 mm profunditate. Systema hyphale monomiticum; hyphae genitales septis simplicibus praeditae, hyalinae, tenuitunicatae vel incrassatae usque 0.75 µm, in subhymenio 2.5-5 µm diametro, in subiculo 3-6(-7.5) µm. Cystiola ad os pori vel ad marginem plicae insidentia, tenuitunicata, cylindrica vel elongato-clavata, in materia luteola semicrystallina inclusa, 25-65 x 5-8 µm. Basidia cylindrica vel clavata, 4-sterigmatophora, basi simplici-septata, 14-22 x 4.5-6 µm. Basidiosporae ovoideae vel ellipsoideae, adaxialiter complanatae, laeves, tenuitunicatae, hyalinae IKI-, 4.3-5 x 2.5-3 µm. Cariem albam efficiens.

ETYMOLOGY: psittacinus, parrot-like, referring to the wide variation of colour from bright reddish purple when fresh to purple, brownish orange, pale orange, or pale yellow-orange when dry.
NOTES: B. psittacinus is readily recognisable in the field by its striking reddish purple colour, the colour variously fading on drying, and the variable poroid to reticulately poroid hymenophore. The species is described here in Byssomerulius Parmasto on account of the hymenophore varying from regularly to reticulately poroid, presence of a continuous hymenium and encrusted cystidioles at the pore mouth or edge of folds, simple septate generative hyphae, and ovoid to ellipsoid, hyaline spores. The species appears to be close to B. hirtellus (Burt) Parmasto (Ginns 1976, as Meruliopsis hirtellus (Burt) Ginns), differing in the colour and more regularly poroid form of the hymenophore.
Because of its conspicuous colour in the field, it is surprising that the species was not recorded earlier by Cunningham (1963, 1965). In PDD, two early collections of B. psittacinus (PDD 7088, 17324) were located under the name Merulius ravenelii Berk. (=Gloeoporus taxicola (Pers.) Gilb. & Ryvarden), a species that differs in colour of the hymenophore and in having allantoid to cylindrical basidiospores and non-encrusted cystidioles.
The variation in colour in dried specimens may reflect maturity of the hymenophore and method of drying. Air drying without heat tends to favour retention of the purple colour, although in heat-dried collections some parts may remain purple while other parts fade to reddish orange or paler.

HOLOTYPUS: New Zealand, Fiordland, Fiordland National Park, Lake Te Anau, Eglington River mouth, on dead wood of Nothofagus ?solandri, M. Izawa, H. Tanaka, L. Ryvarden 39916 & P. K. Buchanan 97/025, 2 May 1997 (PDD 68255; O - isotype).