Dictyosporium triramosum Aramb., Cabello & Cazau
Sexual morph: Undetermined. Asexual morph: Colonies on natural substratum consisting of septate, branched dark brown mycelium and abundant light brown sporodochia. Sporodochia scattered, globose, subglobose or irregularly shaped, up to 200 µm. Conidiophores micronematous, simple or with few branches, flexuous, smooth, hyaline to brown up to 4 µm long. Conidiogenous cells integrated or discrete, globose to subglobose, thin walled, smooth, hyaline, or light brown, 8.1–9 × 4–5 µm. Conidia solitary, dry, holoblastic, cheroid, yellow brown to brown, smooth, 40–60 µm long and 10–13.5 µm wide, with a more or less triangular basal cell, 4.5–5.1 µm wide, from which 3 (occasionally 2) parallel, appressed rows of cells, arise, arranged in two planes, each row with 9–10, thick walled cells of 3–3.5 µm long and 5–5 5 µm wide terminal cells distinctly, hyaline, thin walled, lightly incurved, 5–5.5 µm long and 4.8–5 µm wide. Total number of conidial cells 26–30
Colonies on CMA diameter 20–25 mm at 21 d., effuse, sporodochia abundant, yellow to light brown, scattered in central area, or zonate with 1–3 circles in submargin, up to 200 µm wide. Mycelium mostly submerged, partly supe rficial, composed of branched, septate, smooth, brown to dark brown hyphae, 2–4 µm wide; soluble pigment pale yellow to lightly yellow; reverse colorless, yellow to yellow brown. Conidiophores micronematous, simple or irregularly branched, flexuous, smooth, light brown Conidiogenous cells integrated or discrete, hyaline to brown, doliiform, subglobose, thin walled. smooth, hyaline to light brown, 7.5–8 × 4–4.5 µm. Conidia solitary, holoblastic, cheroid, yellow brown to brown, smooth, 45–62 µm long and 10–13. 5 µm wide, with a more or less subconic basal cell, 4.5–5 µm wide, on which 3 parallel (occasionally 2) appressed rows of cells arise, arranged in two planes, each row with 8–10, thick walled cells of 2.7–3 µm long and 5–5.5 µm wide; terminal cells distinctly, hyaline thin walled lightly incurved 5–5.5 µm long and 4.8–5 µm wide. Total number of conidial cells 26–30.
Freshwater distribution: Buenos Aires (Arambarri 2001)
Arambarri AM (2001) Dictyosporium triramosum, a new hyphomycete from Argentina. Mycotaxon 78:185–189
Fig 1–2. 1. Detail of the conidiogenous cells and conidium on natural substrate, 2. Conidium on culture media. Scale bar = 25 µm (Arambarri 2001)