Cunningham (1965) placed this species in Grifola because of the numerous pilei arising from a common base. However, this species has a brown to blackish, very thin cuticle at the pileus surface, sometimes covered in part by a brown adpressed tomentum. Hyphae of the tomentum are brown, wide, and thick-walled with large, conspicuous clamps; hyphae of the context are similar but paler coloured or more typically hyaline. In these characters the species is similar to Ischnoderma resinosum (Fr.) P. Karst. Spores of I. rosulata are ellipsoid and are smaller than the cylindrical spores of I. resinosum. We consider that Ischnoderma P. Karst. is a more suitable genus than Grifola.

Holotype: PDD 5691 - New Zealand, Taupo, Kaingaroa State Forest, May 1946, G.B. Rawlings, on Pinus radiata D. Don.

Hymenophore annual, compound, rosulate, caespitose, composed of numerous pilei (7-30) arising from a common mycelial base, or less frequently densely imbricate, to 5 cm. diameter. Pilei coriaceous to woody, fan-shaped, sometimes spathulate, to 3 cm. x 25 mm. x 2-5 mm., often laterally attached to one another, growing upright or laterally; surface fawn or bay-brown with umber zones, radiately striate, cuticle absent, replaced by imbricate parallel hyphae with pigmented walls; margin inturned, crenate, dentate; hymenial surface white or cream, sterile margin 2 mm. wide, even, dissepiments not toothed. Context white, of radiately arranged hyphae, 0.25-1.5 mm. thick; generative hyphae 5-6 µ thick, wall 1 µ, freely septate, sparsely branched, with abundant conspicuous clamp connections; numerous linear lactiferous ducts present. Pores to 1.5 mm. deep, in section white or cream, irregular in shape, round, elongated or angular, 100-250 µ diameter, or 3-4 per mm.; dissepiments 50-100 µ thick, of densely woven hyphae, equal, apex even. Basidial type clavate, basidia clavate, 10-12 x 4-5 µ. Spores broadly elliptical, oblong with rounded ends, or sometimes pip-shaped, 3.5-4 x 2-2.5 µ smooth, hyaline, abundant.

New Zealand.

Growing upon burnt wood, soil in the forest, or upon rotting logs and bases of stumps.

In its typical form the species differs from P. anthracophilus in the smaller, thinner, more flaccid pilei, smaller pores, different colour of pores and pilei, and smaller hyaline spores. Variations occur, however; for the Pukematawai specimens are not rosulate, but densely imbricated, and surfaces of pilei are delicately tomentose; specimens from Reefton, though rosulate. are more woody than the others, and have larger and more roughened pilei. They agree in spores and hyphal features.

MIMOSACEAE. Acacia dealbata: Canterbury, Ashburton, 30 m. PINACEAE. Pinus radiata: Auckland, Woodhill, 120 m; Kaingaroa State Forest, 600 m, type collection, P.D.D. herbarium, No. 5691. UNKNOWN HOSTS. Victoria; Realesville. Tasmania, Port Arthur.

Hymenophore annual, coriaceous, compound, composed of numerous pilei (7-30) arising from a common base, frequently densely imbricated, sometimes rosetted. Pilei flabelliform or sometimes spatulate, 1-3 cm wide, 0 .5-2.5 cm radius, 2-5 mm deep, often laterally attached to one another, erect or horizontal; pileus surface fawn or bay with umber zones, radiately striate; without a cortex; margin acute, inturned, crenate, dentate; hymenial surface white or cream, even, sterile border to 2 mm wide. Pores in section white or cream, round, elongated or angular, decurrent, 5-7 per mm (3-4 per mm when decurrent), 100-250 µm diameter, to 1.5 mm deep; dissepiments 50-100 µm thick, equal, apices even or dentate. Context white, 0.25-1.5 mm thick, of closely compacted radiately arranged hyphae ; generative hyphae 5-6 µm diameter, walls 0.5-1.5 µm thick, freely septate, sparsely branched, with clamp connections, encrusted with mucilage granules; conducting hyphae 5-7µm diameter, walls 0.2 µm thick, sparingly septate, contents staining; Hymenial layer to 12 µm deep, a dense palisade of basidia and paraphyses partly embedded in mucilage. Basidia subclavate, 10-12 x 4-5 µm, bearing 4 spores; sterigmata erect, to 4 µm long. Paraphyses subclavate or subcylindrical, 6-10 x 3-5.4 µm. Spores broadly elliptical, oblong with rounded ends, or sometimes pip-shaped, 3.5-4 x 2-2.5 µm, walls smooth, hyaline, 0.2 µm thick.

New Zealand, Tasmania, Australia.

Caespitose upon fallen decayed logs, bases of stumps, soil on the forest floor, or burnt wood.

In its typical form the species may be recognised by the small, thin, flaccid coriaceous pilei, small pares, colour of pores and pilei, and small hyaline spores. Context hyphae bear numerous mucilage granules and are often embedded in mucilage, as are basidia and paraphyses. When decurrent, pore orifices are dentate, but are even elsewhere. Australian and Tasmanian specimens examined are lighter in colour, flabelliform rather than rosulate, but agree in microfeatures.

Type: Lignicolous Fungi; Description: Basidiomata annual, compound, composed of numerous (7–30) pilei arising from a common base, usually overlapping each other but occasionally in a rosette, leathery. Pilei fan-shaped, erect or horizontal, often laterally attached to each other, 10–30 mm wide, 2–5 mm thick. Pileus surface tomentose to velutinate, radiately striate, light brown with darker brown zones, margin inturned, crenate. Pore surface even with a sterile border up to 2 mm wide, white; pores small, 5–7 per mm. Context up to 1.5 mm thick, white. Hyphal system monomitic. Basidiospores broadly elliptical, 3–4 × 2–3 μm, smooth, hyaline.

Distribution: Auckland, Bay of Plenty, Marlborough, Mid Canterbury, Southland.; 1st Record: Cunningham (1948a: as Polyporus rosulatus).

Significance: Causes a brown cubical heart rot in Larix decidua. Entry is gained through trunk wounds created during silvicultural operations (Gilmour 1957). It is of no commercial importance.; Host(s): Larix decidua.