Tremella dysenterica is a species of fungus in the family Tremellaceae. It produces bright yellow, red-spotted, lobed to subfrondose, gelatinous basidiocarps (fruit bodies) and is parasitic on other fungi on dead branches of broad-leaved trees. It was originally described from Brazil and has been recorded elsewhere in the neotropics and in Africa.
Tremella dysenterica was first published in 1895 by German mycologist Alfred Möller based on a collection made in Brazil.
Fruit bodies are gelatinous, bright watery-yellow to deep yellow with orange to scarlet spots and streaks, up to 4 cm (1.5 in) across, and lobed to weakly frondose. Microscopically, the basidia are tremelloid (ellipsoid, with oblique to vertical septa), 4-celled, 14 to 18 by 8 to 12 μm. The basidiospores are ellipsoid, smooth, 5.5 to 8.5 by 4 to 5.5 μm.
Tremella rubromaculata, described from Guatemala without reference to T. dysenterica, appears macroscopically very similar but differs microscopically in having larger basidiospores (8 to 10.5 by 6 to 8 μm) and basidia.
Tremella dysenterica is a parasite on lignicolous fungi, but its host species is unknown, though collections have been noted on pyrenomycetes. It is found on dead, attached or fallen branches of broad-leaved trees.
The species is currently known from Brazil, Belize, and Cameroon.