Colony slow growing uniform, without a pattern, with limited aerial mycelium, margin regular and off white. Hyphae swellings common on some isolates, spherical and irregular, averaging 3.7 ± 1.1 (ranging 1.5–7.4) μm. Sporangia rarely observed on solid agar but produced abundantly in non-sterile pond water, papillate, caducous or persistent, borne terminally on simple sporangiophores, predominantly ovoid to rarely globose or limoniform in shape, averaging 31.7 ± 6.6 × 23.3 ± 6.7 μm (ranging 16.6–55.3 × 12.6–39.2 μm). Papillae averaging 3.0 ± 1.0 × 4.9 ± 0.8 μm and ranging from 1.1–5.5 × 3.2–6.6 μm. Sporangial exit pores 5.4 ± 0.8 μm diameter. Sexual reproduction is homothallic. Oogonia aplerotic, averaging 35.1 ± 3.6 (ranging 24–45.6) μm with 29–80% aborting within two weeks, before the formation of an oospore wall. Oospores averaging 29.8 ± 3.3 (ranging 20.8–39.1) μm, with thin walls and an oospore wall index of 0.19, hyaline to rarely pigmented yellow on maturity. Antheridia paragynous (65%) or amphigynous (35%), mostly club-shaped, rarely spherical, 14.9 ± 3.0 × 11.7 ± 2.5 μm. Growth between 5 and 25 °C, slow (optimum, 3.4 mm day-1, at 20 °C).

holotype: NZFS 4037 (dried culture), ex-holotype living culture NZFS 4037 = ICMP 22750