SPECIMENS EXAMINED: GISBORNE: Urewera National Park; 16 km SE of Ruatahuna, Huiarau Summit, on ground under Nothofagus menziesii, Samuels et al., 1 Jun. 1983 (PDD 45346); Urewera National Park, Lake Waikaremoana, track to Lake Waikareiti, on ground, Samuels (83-163) et al., 29 May 1983 (PDD 45347); Lake Waikaremoana, track between Aniwaniwa and Lake Ruapani, on soil, Samuels et al., 31 May 1983 (PDD 45741).

Stromata solitary, simple, 2.5-5 cm long, tip at first conidiogenous and whip-like; filiform, 1-2 mm diam., surface olivaceous, wrinkled, fleshy; perithecia intercalary, nearly superficial, pyriform, acute, 400-500 µm high x 400 µm wide. Internal tissue white, solid. Asci greater than or equal to 280 µm total length x (11-)13-15( 20) µm, the sporiferous part (210-)217-250(-205) µm, cylindrical; apical ring J+, cylindrical, 6-7 µm wide x 7-10(-12) µm high; 8-spored, ascospores uniseriate with overlapping ends. Ascospores (31-)34-40(-42) x (9-)13-14(-16) µm, fusiform with subacute ends, inequilateral, one side flat and the other side rounded, dark brown, near opaque; slit 22-26 µm long, straight, parallel to long axis of the ascospore. Conidiophores in vivo forming a compact paliade along the tip of the conidiogenous stromata; palisade 50-100 µm deep; conidiogenous cells cylindrical, c. 4 µm wide, straight, smooth, pale brown; conidiogenous loci terminal, leaving a 1 µm wide refractive, frill-like abscission scar after conidial dehiscence. Conidia (4.0-)5.5-7.0 x 3.0-4.0 µm, subglobose to elliptical, tip sometimes acute, with a 0.5 µm, refractive basal frill, very pale brown, smooth.

DISTRIBUTION: NORTH ISLAND: Gisborne.

HABITAT: On ground under living Nothofagus spp. and on rotten wood of Nothofagus spp.

A typo differt in ascospores (31-)34-40(-42) x (9-)13-14(-16) µm. Holotypus: PDD 44428.

X. theissenii var. macrospora seems to differ from the typical variety chiefly in the larger size of its ascospores. It has been found only in association with Nothofagus spp. and might grow from living rootlets.
This variety is closely related to Xylaria taxonomic species 1 (see above).

HOLOTYPE: GISBORNE: Urewera National Park, 15 km SE of Ruatahuna along State Highway 38, Taupeupe Saddle, on well rotted wood of Nothofagus sp., Samuels (82-265) et al., 3 Nov. 1982 (PDD 44428).