Hymenophore to 15 x 10 cm., 5-16 mm. thick, with white pore mouths, turning brown where bruised and drying smoky brown or fuscous; surface undulating, of groups of pores overlapping others, leaving vertical sections of pores exposed to 10 mm., when longitudinally striate; margin obscure, abrupt, 1-2 mm. wide, dingy white or isabelline. Pores not in strata, obliquely inserted, to 15 mm. deep, irregularly angular, polygonal, or elliptical, 0.2-1 mm. diameter, or 0.2-0.3 x 1 mm., dingy white when fresh, drying wood colour with fuscous margins; dissepiments 50-200 µ thick, commonly 75-100 µ, equal, of woven gelatinized mainly parallel hyphae, margins even, not velutinate. Context to 1 mm. thick, isabelline, of densely woven hyphae; skeletal hyphx 3-4 µ thick, lumen 2 µ, hyaline, aseptate, unbranched, staining strongly; generative hyphae 1.5-2 µ thick, delicate walled, septate, branched, clamp connections present, scanty. Basidial type clavate, basidia appearing cruciate owing to adhering spores, clavate, 8-10 x 4-5 µ, sterigmata to 10 µ long, embedded in a gelatinous matrix, forming a dense palisade. Spores elliptical, ovate, or slightly kidney shaped, 4.5-5 x 2.5-3 µ, hyaline, smooth, cemented together at the apices of the basidia.

New Zealand.

Specimens were found upon the interior of a rotting stump, growing obliquely, and extending down the bark on the lower surface. The elongated pores occur in overlapping groups and give to the surface of the hymenophore an undulate appearance. When fresh pore mouths are white--contrasting with the isabelline context--but soon change on drying or where bruised to a dingy wood colour. Basidia are embedded in copious mucilage which tends to hold spores upon their apices in groups of four, so that basidia appear cruciate when viewed from above. Skeletal hyphae are often coated with crystals.

On dead wood of (1) Beilschmiedia tawa Waiotapu, 17 June 1950, J. M. Dingley; (2) B. tawa, Thames, Kauaeranga Valley, 22 Oct. 1950, J. M. Dingley; (3) Cordyline australis. Hamilton, Claudelands Reserve, Nov. 1946, G. H. Cunningham (Poria cordylina HOLOTYPE, PDD. 5248).

Fructifications coriaceous, warm greyish when fresh, turning brown where bruised, drying smoky brown or fuscous, to 15 x 10 cm, 5-16 mm thick. Pores non-stratose, often obliquely inserted and incomplete, to 15 mm deep, irregularly angular or polygonal, (l)-2-4 per mm, dingy white when fresh, drying wood colour. Dissepiments thin equal, fimbriate. Context and trama composed of interwoven, thick-walled hyphae, solid or with narrow lumina, sparingly branched, strongly crystal incrusted, rarely septate, l.5-3.5 µm. diam., clamp connections absent. Thin-walled hyphae branched, septate, 1.5-2.5 µm diam., clamp connections present. Hymenium lining pores; probasidia obovate to pyriform, with basal clamp connections, 7.5-9-8 x 5.5-7 µm, becoming longitudinally cruciate-septate; sterigmata 5-10 µm. long. Basidiospores curved-cylindrical to allantoid, hyaline, smooth, apiculate, 5-7 x 2.2-3µm. Germination not observed.

Angiosperm and gymnosperm wood.

ILLUSTRATIONS. Teixeira & Rogers, Mycologia 47: 411, f. 1-7. 1955; Macrae, Mycologia 47: 813, f. 1. 814, f. 2-18. 1955.

New Zealand collections of Aporpium caryae are considerably darker in colour and more resinous in texture than specimens from other countries, as noted by Teixeira & Rogers. Microscopically they are indistinguishable. Teixeira & Rogers described the occasional occurrence of thin-walled cystidioles in the hymenium but Macrae (1955, p. 815) stated that cystidia were absent. No cystidia-like structures were observed in the above collections.
Macroscopically, A. caryae resembles a Poria and could easily be mistaken for a member of that genus were it not for the cruciate-septate basidia.

TYPE LOCALITY:
Pennsylvania, U.S.A.