[Notes from Kew Type specimen, PRJ 2010] Kew images.

Ascomata subglobose, flattened when dry, up to 25 mm diam, medium brown, with warts on the exterior, often covered with sand. Warts irregularly polygonal, about 0.4-1 mm broad in the largest dimension at the base, 0.4 mm high, with parallel lines on the surface.
Peridium 500-1000(-1300) µm thick, including warts 300-450 µm high, with two distinct layers. Outer layer 200-300 µm thick, pale brown, composed of brown pigmented cells up to 24 µm diam, forming a textura angularis. Inner layer 300-700(-1000) µm thick, including the inner part of the warts, pale yellowish brown, composed of hyphae up to 5 µm diam, forming a very loosely interwoven textura intricata, often giving rise to empty irregular locules.
Gleba yellowish brown, with paler sterile veins composed of pale brown hyphae up to 8 µm diam forming a loose textura intricata, separating the fertile chambers. Fertile chambers numerous, lined with hymenium, completely filled with ascospores and the remnants of asci. Paraphyses cylindrical, nearly colourless, slender, the same length as asci, hard to observe.
Asci cylindrical, about 200 x 35 µm, thin-walled, fragile, with only the remnants of their walls visible in older ascomata, mostly 8-spored, not turning blue in Melzer's reagent, with a cyanophilic wall.
Ascospores uniseriate within the asci, globose, pale brown, 17.5-22 µm diam excluding ornamentation, with walls up to 1.5 µm thick, coarsely ornamented with strongly cyanophilic, hemispherical and sometimes confluent warts up to 3 µm high and 4 µm diam at the base.

Ab aliis subgeneris sui speciebus differt non solum quod habet ascomata verruculis induta conspicuis in quibus videantur lineae parallelae, sed etiam quod verruculi maiores quam in speciebus aliis sunt ascosporis ornamento.

Etymology: phymatodeus (Latin: "warty") describing the ascomata.Notes on New Zealand Labyrinthomyces species
Labyrinthomyces phymatodeus differs from all other species in the subgenus in having ascomata with conspicuous warts on which parallel lines are present, and in having ascospores ornamented often with larger hemispherical warts. It also differs from L. varius and Labyrinthomyces sp. (PDD 48338) in having its glebal fertile chambers remaining filled with ascospores; from L. turbinatus in having dark brown ascomata which are not turbinate, but which have a thicker and differently structured peridium; and from L. tesselatus in having larger ascomata again with a thicker and differently structured peridium.
The dark brown, warty ascomata, the glebal structure and the distribution of L. phymatodeus made it so similar to the description of the monotypic genus, Dingleya Trappe (Trappe, 1979), that the specimen was found filed under the name "Dingleya sp." in K. Examination of type material, however, showed that ascospores of D. verrucosa Trappe (PDD) are ellipsoid, with an amorphous, ridged ornamentation. Labyrinthomyces phymatodeus is thus sufficiently different in ascospore morphology that it cannot be placed in Dingleya. The globose ascospores ornamented with hemispherical warts and glebal structure of L. phymatodeus do, however, agree well with the circumscription of Labyrinthomyces.
Labyrinthomyces turbinatus differs from L. tesselatus in having larger, pale brown, often turbinate ascomata, often with flattened polygonal warts, and in having ascospores ornamented with sparse, irregular, smaller warts (figs 10, 14-15). It differs from L. varius in having ascomata which are not tomentose, glebal fertile chambers remaining filled with paraphyses, asci and ascospores, paraphyses equalling the length of asci, and much thinner ascus walls.

Typus: New Zealand: North Island, Taranaki, under Leptospermum sp., 1979, H. Lintott (holotype, K).