CONIFERAE. Dacrydium cupressinum: Auckland, Waipoua Kauri Forest, 120 m; Mountain Road, Henderson Valley, 200 m; Lake Waikareiti, 700 m. Phyllocladus alpinus: Canterbury, Hermitage, Mt. Cook, 850 m.

Hymenophore perennial, ceraceous-suberous, closely adherent, usually resupinate, rarely effusedreflexed, forming irregular areas 4-30 x 2-10 cm, with a few outlying islands; hymenial surface cream, drying pallid ochre or reddish-buff, somewhat tuberculate, finally creviced; margin white or cream, adherent, cliff like and bordered by a black line (in some North American specimens margins are reflexed, sulcate, naked, black, 3-10 mm radius). Context isabelline with darker base, 0.5-1.5 mm thick, composed of erect hyphae compacted into a pseudoparenchyma, embedding numerous vesicles and, in lower layers, masses of crystals; skeletal hyphae 3-3.5 µm diameter, walls 1 µm thick; generative hyphae 2-2.5 µm diameter, walls 0.2 µm thick, with clamp connections. Vesicles arranged in irregular rows in context and hymenium, scarcely projecting in the current layer, collapsing and disappearing from lower zones, pyriform, obovate, fusiform, or subglobose, 16-24 x 10-16 µm, contents granular and with oil globules, in the hymenial layer some elongated with broad bases and narrow necks, to 65 x 12 µm. Hymenial layer to 40 µm deep, a scanty palisade of basidia, paraphyses, and vesicles. Basidia subclavate, 20-24 x 4-5 µm, bearing 4 spores; sterigmata arcuate, slender, to 4 µm long. Paraphyses cylindrical, some with acuminate apices, 14-22 x 3.5-4 µm. Spores elliptical, obovate, a few pip-shaped, apiculate, 4.5-5.5 x 3-3.5 µm, walls smooth, hyaline, 0.2 µm thick.

DISTRIBUTION: North America, West Indies, Western Europe, South Africa, New Zealand.

HABITAT: Effused on bark of dead trunks.

Commonly resupinate, the species would normally be regarded as a Corticium, since it possesses the microstructure of stratose species of that genus, save that the hyphal system is dimitic. In North America pileate forms have been collected, pilei being narrow and scarcely more than upturned margins with a hard, horny, naked black cortex. From S. purpureum, which also bears vesicles, it may be separated by the thick fructifications with ochre or buff hymenial surface, stratose context with numerous vesicles scattered throughout, and erect hyphae of the layers of the context. Vesicles are usually pyriform or obovate; beneath the hymenial layer arise a few which, fusiform or ventricose in shape, may attain a length of 65 µm, penetrate the hymenial layer and simulate gloeocystidia. In the base of the context, hyphae become discoloured and somewhat cemented; they produce the black line bordering the hymenium of resupinate specimens and form the cortex of pileate plants. The species was made the type of Cystostereum Pouzar (1959, p. 18).

TYPE LOCALITY: Massachusetts, U.S.A.