Flagellostrigula
Genus of lichens
From Wikipedia, the free encyclopedia
Flagellostrigula is a small genus of lichen-forming fungi in the family Strigulaceae.[1][2] It was established for a distinctive, bark-dwelling lineage known chiefly from its asexual stage. The type species is Flagellostrigula laureriformis, and a second species, F. pyrenuloides, was transferred to the genus in 2025. The genus is marked by unusually large asexual fruiting bodies (pycnidia) and by macroconidia that bear a single, long, whip-like gelatinous appendage at one end. Both species are found in tropical to subtropical regions of the Americas, growing on tree bark.
| Flagellostrigula | |
|---|---|
Scientific classification  | |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Dothideomycetes |
| Order: | Strigulales |
| Family: | Strigulaceae |
| Genus: | Flagellostrigula Lücking, S.H.Jiang & Sérus. (2020) |
| Type species | |
| Flagellostrigula laureriformis (Aptroot & Lücking) Lücking, S.H.Jiang & Sérus. (2020) | |
| Species | |
|
F. laureriformis | |
Taxonomy
Flagellostrigula was proposed in 2020 by Robert Lücking, Shu-Hua Jiang, and Emmanuël Sérusiaux to accommodate a morphologically unusual species originally described as Strigula laureriformis; in establishing the genus, that species was transferred as Flagellostrigula laureriformis.[3] Molecular data were not yet available, so the genus was originally delimited by morphology. It resembles Dichoporis in having macroconidia with a single septum, but differs in key details of the asexual structures.[3]
In 2025, André Aptroot and Lücking made the new combination Flagellostrigula pyrenuloides (basionym Strigula pyrenuloides, 2020), based on material from Brazil (Pantanal, Mato Grosso do Sul), making the genus no longer monotypic.[4] Reports from Costa Rica and Brazil match the concept of the type species, while a Chinese record with slightly different pycnidial morphology may represent an additional, as yet unnamed species within Flagellostrigula rather than F. laureriformis in the strict sense.[5][3]
Description
The thallus (lichen body) of Flagellostrigula is greenish and corticate (with a protective outer cortex), growing on bark. The photobiont partner is the green alga Trentepohlia. Sexual reproductive structures (ascomata) are unknown for the genus; all confirmed material is from the asexual state.[3]
Pycnidia (asexual fruiting bodies) are common, conspicuous, and relatively large for the group, hemispherical to wart-like, and up to about 0.8 mm in diameter. They are covered by a noticeably thick layer of thallus tissue. Conidia are produced at the tip of the conidiogenous cell (acrogenous), and only macroconidia are known. These macroconidia are one-septate (two-celled), broadly rod-shaped, hyaline (colourless), and bear a single, very long, flagelliform (whip-like) gelatinous appendage at one end that measures roughly 15–35 × 1 micrometres and is typically three to four times the length of the conidium. No secondary metabolites (lichen products) have been detected in the thallus.[3]
Habitat and distribution
Flagellostrigula is corticolous (bark-dwelling) in terrestrial tropical to subtropical habitats. F. laureriformis is documented from the Neotropics, including Costa Rica and Brazil, and the Chinese material with deviating pycnidia may represent a separate species within the genus.[3] F. pyrenuloides was described from the Brazilian Pantanal, consistent with a Neotropical distribution for the group as currently known.[4]