MYRTACEAE. Eucalyptus hemiphloia: Victoria, Burkes Flat, Bealiba. Eucalyptus spp.: Auckland, Whakarewarewa, 450 m. Queensland, Redbank Plains. New South Wales, Between Booral and Robertson; Wangan; Landsdowne; Macquarrie Pass; Dugong. South Australia, Encounter Bay; National Park, Mt. Lofty Range. Victoria, Macraes Creek, Beenak; Monbulk Forest, Dandenong Ranges.

Hymenophore annual, cretaceous, adherent, at first composed of numerous orbicular or linear small colonies 2-10 mm across, coalescing to form effused areas 11-14 x 1-2 cm; hymenial surface chalk white, even, at length deeply and areolately creviced; margin thinning out, at first fibrillose, later definite and cliff-like, adherent. Context white, to 250 µm thick, basal layer of compact hyphae densely intertwined and almost pseudoparenchymatous, intermediate layer scanty, of erect hyphae; generative hyphae 3-5 µm diameter, walls 0.25 µm thick, naked, without clamp connections. Acanthophyses arising from the surface of the basal layer and forming a dense palisade, coralloid, with lateral branches, spinose throughout. Gloeocystidia commonly fusiform, oval, or obpyriform, 32-72 x 18-50 µm, contents orange when fresh. Hymenial layer occupying the greater part of the context, a close palisade of basidia, paraphyses, and acanthophyses. Basidia cylindrical or slightly clavate, 65-110 x 20-25 µm, bearing 4 spores; sterigmata arcuate, subulate, to 32 µm long. Paraphyses ovate, fusiform, or subclavate, varying in length and shape, deeply embedded, 35-80 x 8-16 µm. Spores elliptical, apiculate, 25-36 x 16-20 µm, walls covered with irregular aculeae to 3 µm long, hyaline; 1 µm thick, amyloid.

DISTRIBUTION: Australia, New Zealand.

HABITAT: Effused on bark or decorticated wood of dead branches.

The type collection in Kew herbarium, ex "Wangaretta, Victoria" consists of eight small, irregularly orbicular colonies 1-5 mm wide. It is immature since spores were not found. Sections agree with the collections from Australia listed above, save that paraphyses are more clavate. The description given differs in several particulars from that of Hoehnel & Litschauer (1907, p. 809) which was drawn from specimens collected near the Murray River, Victoria. For they had described a different type of acanthophysis, and stated that spores were smooth. Basidia and paraphyses arise from the surface of the basal layer and are completely embedded in masses of acanthophyses which form the greater part of the context. At maturity basidia become elongated and. project above the hymenium, shed their spores, then collapse. Paraphyses remain deeply embedded. Gloeocystidia are scanty or abundant, apparently absent from some collections, assume many shapes, vary appreciably in size, and when fresh contain orange contents. In a previous paper (1956b, p. 259) I stated they were not present; but in a recent collection they were readily seen, and on re-examination of the other collections were found in some but not all, by aid of a differential stain. Fig. 101 was prepared from a section without gloeocystidia. Acanthophyses are coralloid and arise mainly from the surface of the basal layer. They are freely branched and usually clothed throughout with spines which in turn may branch. Spores are the largest recorded for the genus. In lactic acid aniline blue mounts they appear to be almost smooth; but in Melzer's reagent are seen to be covered with irregular aculeae which may reach a length of 3 µm. Early stages are cupulate or pezizaeform, and fructifications may remain so, or colonies fuse to form effused fructifications typical of most species of Acanthophysium. Pezizaeform plants could be placed under Aleurodiscus, but as their structure is corticioid, acanthophyses coralloid, and the species close to A. coralloides, it has been treated as an Acanthophysium.

TYPE LOCALITY: Victoria, Australia.