What You Should Know
Bisporella sulfurina is a species of fungi in the group Ascomycota. Fresh fruit bodies are stalkless, bright yellow cups, with paler margins and exteriors. As they age, they become paler yellow or almost white. they reach up to 1 mm in diameter. They grow on old stromata of pyrenomycete fungi, especially those of the genera Diatrype, Diatrypella and Hypoxylon, which have, in turn, fruited on decaying wood from deciduous trees. They grow gregariously on their host and often two or three will be seen tightly clustered together.
First described by Lucien Quélet, and given its simplified Asian name by Steven E. Carpenter in 1974. Bisporella sulfurina belongs to the genus Bisporella, order Helotiales, classis Leotiomycetes, divisio Ascomycota, and regnum Fungi.
Bisporella sulfurina Mushroom Identification
Apothecia 0.5-1.0 mm broad, sessile, at first urn-like, centrally concave, becoming cushion-shaped to discoid; hymenium glabrous, bright yellow to citrine, slightly translucent; exterior colored like the disc or paler; margin more or less even, lacking hairs; context soft, fleshy, yellowish; odor and taste not investigated.
8.0-11.0 (13.0) x 2.0-2.5 µm, narrowly ellipsoid to subfusoid, occasionally curved, hyaline, one-septate at maturity, some with droplets; asci eight-spored, uni to biseriate, the tips inamyloid.
On hardwoods, gregarious to clustered, fruiting in association with a pyrenomycete; seldom collected because of its size, but probably common.
Bisporella sulfurina Look-Alikes
Bisporella citrina is a common, larger species, not associated with a pyrenomycete. It typically fruits gregariously rather than clustered on bark-free hardwoods. Both species have two-celled ascopores at maturity, but the spores of Bisporella citrina are distinctly broader. A third Bisporella, B. pallescens, forms small, whitish cups on hardwoods, and like Bisporella sulfurina, fruits on the surface of another fungus, conidial forming taxa called Bispora antennata.
Bisporella sulfurina Synonyms
Calycella sulfurina (Quél.) Boud. 1907
Calycina sulfurina (Quél.) Kuntze 1898
Helotium sulfurinum Quél. 1880
Photo 1 - Author: Jerzy Opioła (Creative Commons Attribution-Share Alike 4.0 International)
Photo 2 - Author: Jerzy Opioła (Creative Commons Attribution-Share Alike 4.0 International)