ON HUMUS. Auckland, Rangitoto Island; Kawau Island; Avondale; Riverhead; Mt. Maunganui; Tokoroa; Whakarewarewa. Hawke's Bay, Napier. Wellington, Tangimoana; Weraroa; Ngaio; Tinakori Hills. Nelson, Appleby; Totara Flat. Canterbury, Ashburton; Hammer State Forest. South Australia, Snuggery; Mt. Burr; National Park; Hanson; Williamstown; Mt. Gambier; Kalangadoo; Kuitpo; Clarendon. Western Australia, Mundaring.

Hymenophore annual, membranous, humicolous, sometimes encrusting living or dead plants, forming pilei of diverse shapes and sizes. Pilei applanate, flabelliform, sometimes merged to form erect rosettes, 1-10 cm tall and broad; surface ferruginous or umber, covered with strigose tufts which are concolorous or darker and sometimes imbricated hymenial surface ferruginous or umber, often vinaceous, radiately striate, even or finely tuberculate; margins crenate, sometimes freely lobed or toothed, bluntly rounded or torn, concolorous. Context 1-5 mm thick, ferruginous, basal layer forming the greater part of the fructification, of loose parallel hyphae associated with parallel strands of closely compacted hyphae; generative hyphae 4-6 µm diameter, walls 0.2-0.5 µm thick, pallid yellow brown, naked, freely branched often at a wide angle, septate, with clamp connections. Hymenial layer to 90 µm deep, a close palisade of basidia and paraphyses. Basidia subclavate, 32-45 x 8-10 µm, bearing 2-4 spores; sterigmata arcuate, to 8 µm long. Paraphyses subclavate, 22-35 x 6-8 µm. Spores subglobose or irregularly oval, 8-10 µm diameter, or 8-11 x 7-9 µm, walls sinuate, finely sparsely verruculose, pallid ferruginous, 0.5 µm thick.

DISTRIBUTION: Cosmopolitan.

HABITAT: Encrusting humus under pines.

Although only a few collections are listed, the species may be found in any plantation of Pinus radiata. It has evidently been introduced with seeds or plants, since it is not found in any other habitat. There is no evidence showing that the fungus forms a mycorrhiza with pines; nor is the species a plant parasite, though known occasionally to kill pine seedlings by growing around stems and smothering them. In macrofeatures the species varies so considerably that it is difficult to draw an accurate description of the fructifications. Commonly plants grow over pine needles, humus, and soil under pines, the mycelium encrusting the surface over an area of many square metres. From the mycelium pilei arise. Usually flabelliform, they may merge to form erect rosettes, or sometimes campanulate pilei.

T. crustosa was erected on a form with small flabelliform fructifications. Pilei may remain entire; or more commonly become torn into few or several lobes, T. laciniata being a name applied to specimens displaying the latter condition. Colour may range from ferruginous to dark umber, or umber with a vinaceous tinge; the pileus surface may be clothed with coarse strigose tufts, slender down-pressed bundles of hairs, or remain almost smooth. The hymenial surface may be even, or, as often tuberculate or radially striate. Most conditions may be found in one ample collection, showing that these are merely variable growth conditions. Spores are subglobose or more often oval, walls bearing 3-5 rounded lobes, giving them a sinuate appearance. Spore walls are covered with short, scanty, broad-based verruculae, which may be hyaline or tinted brown like the spore wall.

TYPE LOCALITY: Europe.

Type: Mycorrhizal Fungi; Description: Basidiomata formed from subsessile pilei of diverse shape and form, dimidiate or spuriously infundibuliform, often in imbricating rosettes, up to 120 mm wide, sometimes encrusting living or dead plants. Pilei applanate, flabelliform, surface ferruginous, umber or vinaceous, covered with strigose tufts, margin crenate, concolorous. Pore surface inferior, even or finely tuberculate, ferruginous, umber or vinaceous. Context ferruginous, 1–5 mm thick, fibrous. Basidiospores either globose 8–10 μm in diameter, or irregularly oval, 8–11 × 7–9 μm, 0-septate, sparsely echinulate, pallid ferruginous.

Distribution: Northland, Bay of Plenty, Taupo, Wanganui, Gisborne, Hawkes Bay, Nelson, Buller, North Canterbury, Mid Canterbury, South Canterbury, Dunedin, Otago Lakes, Southland.; 1st Record: Chu-Chou (1979).

Notes: This fungus has been also recorded under ‘Radicicolous Basidiomycota’ because it is a root-inhabiting fungus that occasionally smothers young seedlings. The following account contains additional information relating to its mycorrhizal function. ASSOCIATED PLANTS: Pinus radiata, Pseudotsuga menziesii.

Significance: Isolated from and shown experimentally to be a mycorrhizal partner of Pinus radiata (Chu-Chou 1979) and isolated from Pseudotsuga menziesii (Chu-Chou & Grace 1983a). Reported to be ineffective in promoting the growth rate of P. radiata seedlings (Chu-Chou & Grace 1987).; Host(s): Pinus radiata, Pseudotsuga menziesii.