MYRTACEAE. Metrosideros excelsa: Auckland, Little Barrier Island. Metrosideros robusta: Auckland, Silverdale, 35 m; Waitakere Ranges, 300 m. UNKNOWN HOSTS. South Australia, Kangaroo Island; Mylor. New South Wales, Moruya (herb. Kew under H. fuliginosa).

Hymenophore resupinate, annual, sometimes perennial, membranous-brittle, adherent, effused forming irregular areas 3-6 x 2-3 cm; hymenial surface seal-brown, dark umber, or chocolate, irregularly tuberculate, velutinate, not or tardily creviced; margin thinning out, cinnamon, fibrillose, loosely attached. Context dark umber or sepia, 150-300 µm thick (to 800 µm in stratose specimens), sometimes vertically fibrillose where fractured, of mainly erect hyphae and a cortex of parallel cemented hyphae deeply coloured and bearing abhymenial hairs of irregular length; generative hyphae 4-5 µm diameter, walls 0.5-1 µm thick, dark yellow-brown, some submoniliform. Setal layer to 250 µm deep, composed of 2-5 overlapping rows of setae and stout erect hyphae; setae irregularly fusiform, some projecting to 45 µm, apices acute, 40-70 x 8-12 µm, walls naked, rich chestnut, lumena narrow. Hymenial layer to 30 µm deep, a close palisade of basidia, paraphyses, and paraphysate hyphae. Basidia subclavate, 12-16 x 3.5-4 µm, bearing 4 spores; sterigmata slender, erect, to 4 µm long. Paraphyses cylindrical, 18-24 x 4-5 µm, walls tinted yellow. Paraphysate hyphae scanty, projecting to 30 µm, cylindrical, many submoniliform. Spores suballantoid, 3.5-4 x 1-1.25 µm, walls smooth, hyaline, 0.1 µm thick.

DISTRIBUTION: Ceylon, South Africa, Australia, New Zealand.

HABITAT: Decorticated wood of dead branches and trunks associated with a pocket rot.

Collections agree with the type, part of which was examined in Kew herbarium. The species may be identified by several unusual microfeatures, as the occasional submoniliform hyphae which, together with normal hyphae, appear in the context, abhymenial hairs, and as paraphysate hyphae; erect hyphae of the context; presence of a stout cortex of parallel hyphae; delicate basidia and the monomitic hyphal system. Some of these features vary appreciably in different collections. In the type the context consists of a compact dense layer of parallel hyphae, the cortex, and erect hyphae forming a loose palisade between this and the setal layer. About one-third of the hyphae are submoniliform, a feature not mentioned by Petch. In one New Zealand collection in which plants are somewhat immature, a dense cortex is present, and the setal layer arises directly from this with, between setae, erect palisade hyphae, a few of which are submoniliform. In other New Zealand collections the context is stratose, consisting of several setal layers with hyphae between. The latter are erect as in the type, and a few exhibit submoniliform areas as is shown in fig. 152. Basidia and spores were not described by Petch, nor found by Talbot (1951, p. 49). They are nevertheless present in the type and all New Zealand collections. Basidia are delicate, scanty, and smaller than the cylindrical coloured paraphyses.

TYPE LOCALITY: Hakgala, Ceylon.