Fruiting body a stalked to nearly sessile sporangium, scattered to clustered (rarely crowded or in fascicles of 2 or 3), up to 2 mm high. Sporotheca globose to irregularly ovoid (rarely broadly cylindrical or narrowed in the middle), mostly yellow but varying to ochraceous, beige, light brown, or greenish, 0.3–0.7 mm in diameter. Stalk slender to moderately thick, smooth, sometimes weak, pallid to dark brown, one-third to one-half the total height of the fruiting body. Hypothallus inconspicuous. Peridium persisting in mature fruiting bodies only as a distinct calyculus, the latter shallow, plicate, marked with coarse papillae and partial reticulations. Capillitium elastic, persistent, open, expanding laterally and longitudinally, consisting of filaments 3–6 µm in diameter, frequently with swellings, expanded junctions, and occasionally with clavate or rounded free ends, marked with cogs, transverse bands, and spines, the latter sometimes connected by ridges. Spores yellow to ochraceous in mass, faintly yellow to colourless by transmitted light, nearly smooth with a few scattered warts or delicately warted over large areas, 6–10 µm in diameter. Plasmodium white.

Reported from Africa, Asia, Australia, Europe, North America, and South America (Martin & Alexopoulos 1969, Mitchell 1995, Ukkola 1998). First reported from New Zealand by Rawson (1937), based on a specimen collected in South Canterbury. Also known from Auckland, North Canterbury, and the Auckland Islands.

Decaying wood, sometimes occurring on the bark of living trees.

Martin & Alexopoulos (1969), Nannenga-Bremekamp (1991), Neubert et al. (1993), Lado & Pando (1997), Ing (1999).

In most instances, Arcyria pomiformis can be easily recognised by its yellow color, the more or less ovoid shape of the sporotheca, and the evenly expanding and conspicuously wide-meshed capillitium. However, some specimens may resemble A. cinerea. Farr (1962) compared the morphological features of A. pomiformis and A. cinerea in considerable detail and concluded that the most reliable feature that could be used to separate the two species was the ornamentation of the inner surface of the calyculus (smooth to faintly punctate or reticulate in A. cinerea and marked with coarse warts and partial reticulations in A. pomiformis).