Ascocarps immersed in host hypodermal tissue, flask-shaped, 0.3-0.7mm diam., initially raising the covering host tissue into a small pustule, which then splits to expose the white, crystalline ascocarp margin. Ascocarp margin extending across top of the hymenium, and opening by a small, irregularly-shaped aperture near centre of the ascocarp. Margin in transverse section up to 80um wide, comprising three layers; 1, a wall layer, up to 20um wide, of hyaline, 1.5-2um diam. hyphae, extending from a short distance below the subhymenium to half way up the ascocarp margin; 2, a crystalline, 30um wide, wedge-shaped layer in the top half of the margin, extending partially over the hymenium; 3, a 30um wide layer of cylindrical, unbranched periphyses lines the wall and crystal layers, periphyses amyloid in upper half of the margin. Subhymenium !0-12jjm wide, of thin walled, hyaline cells, 3-5um diam. Paraphyses filiform, i.5-2jjm diam., undifferentiated at apices, net extending beyond asci. Asci 8-spored, cylindric, 163-195 x 5-6um; wall thickened up to 3.5um at apex, with a small central pore, the upper 10-20um of the ascus wall faintly and diffusely amyloid. Ascospores initially filiform, extending almost the length of the ascus, disarticulating into nonseptate, 1.8-2 x l.2um part-spores. Synanamorphs known only from culture. Ascospores germinating on Difco cornmeal dextrose agar within 21 h. After six weeks growth on oatmeal agar at 20 C colonies 6-7cm diam.; aerial mycelium low, white, cottony to felted; agar pale brown. Pale brown conidiomata scattered on agar surface, 3-4 loculate, walls 10-25um wide, of hyaline to very pale brown, thin walled hyphae. Pycnidial locules are of two types. The first type of locule with conidiogenous cells cylindrical, unbranched, 8-15 x 1.5-2um, sympodial, with several broad scars near apices; conidia hyaline, nonseptate, more or less clavate in shape, apex broadly rounded, base truncate, often slightly curved,3.2-4 x 1.2-1.upm. The second type of locule with the inner-most layer of wall hyphae extending into the pycnidial cavity, forming occasionally branching, closely septate chains of cells. The chains disarticulate into nonseptate, hyaline, straight or slightly curved arthroconidia, 2.2-3.5 x 0.8(-1.0)um. Habitat: known only from type collection on a dead twig Specimen examined: New Zealand, Bay of Plenty, Te Puke DSIR Research Orchard, on Actinidia deliclosa, G.J.Samuels S.R.Pennycook, 21.VI. 1982 (PDD 45045 - Holotype).