Fungal Family Tree Rewritten as New Family Funiliomycetaceae Emerges from a 145-Year-Old Genus

One of mycology’s longest-running taxonomic headaches has finally been untangled. In a study published in IMA Fungus, researchers led by Lixue Mi, Kevin Hyde, Huyue Song and Dongmei Hu have shown that the genus Dactylaria, established by Saccardo in 1880, is a sprawling collection of unrelated fungi masquerading under a single name. Their solution is sweeping: a brand-new fungal family, Funiliomycetaceae, carved out of the order Amphisphaeriales, a new species named Funiliomyces jiangxiensis isolated from the roots of a prized Chinese medicinal plant, and the formal transfer of ten previously described species into the genus Funiliomyces. The work is a textbook example of how DNA sequencing is forcing the fungal tree of life into sharper focus, dismantling names that once looked sensible under the microscope but collapse under genetic scrutiny.

Dactylaria has always been a suspect genus. Its members are hyphomycetes, asexual fungi that produce spores on distinctive stalks bearing tooth-like structures called denticles, and for more than a century species were classified almost entirely on such microscopic features. De Hoog’s 1985 revision recognized 41 species in four sections, and by the time Goh and Hyde published their landmark review in 1997 the count had climbed to 82, with 14 more added in the years that followed. Today Index Fungorum lists 134 epithets under the name. The problem, the new study confirms, is that this morphological similarity is deceptive. Species that produce denticulate conidiogenous cells have evolved independently in many unrelated lineages, so the genus became a taxonomic dumping ground for lookalikes rather than a genuine evolutionary group.

The scale of the polyphyly is striking. The researchers compiled all available LSU ribosomal RNA sequences for Dactylaria species in GenBank, covering 26 of the 31 species with molecular data, and built a phylogeny spanning the major classes of Pezizomycotina, the enormous subdivision of fungi that includes most sac fungi. The result: 22 Dactylaria species were scattered across six different classes, including Orbiliomycetes, Leotiomycetes, Eurotiomycetes, Sordariomycetes, Dothideomycetes and even Lecanoromycetes, the class that contains many lichens. Sixteen species clustered in Sordariomycetes, while four others, including the type species Dactylaria purpurella itself, could not be confidently assigned to any known class at all. In other words, the founding species of the genus sits in evolutionary limbo, and most of its supposed relatives are not relatives at all.

The fate of Dactylaria purpurella illustrates just how unstable the situation has been. Originally described from dead leaves of Castanopsis cuspidata var. sieboldii in Japan, the type species has been bounced around the fungal tree by successive studies. ITS-based analyses placed it near Ochroconis; LSU-based work by Réblová in 2009 showed it forming an isolated lineage apart from other Dactylaria species; later studies suggested affinities with Magnaporthales or Venturiales. The new analysis finds it forming a distinct lineage with D. humicola and D. dimorpha that remains incertae sedis, unplaced within any recognized class of Pezizomycotina. Until more sampling and multi-locus data are available, the true identity of the genus Dactylaria remains an open question, a humbling reminder that a name in continuous use since 1880 can still lack a secure home.

Amid this chaos, one lineage stood out as coherent. Funiliomyces biseptatus, described by Aptroot in 2004 from a dead bromeliad leaf in a Brazilian rock field, was known only from its sexual morph, producing black subglobose fruiting bodies and pale brown, torpedo-shaped ascospores divided by two septa and furnished with mucilaginous appendages. Meanwhile, several recently described Dactylaria species, identified from asexual morphs on plants in Hawaii, Brazil, Colombia, Korea and Australia, kept clustering near Funiliomyces in published trees but sat unresolved within Amphisphaeriales, an order of sac fungi whose crown age has been estimated at around 133 million years. The new study’s multi-gene analysis, combining LSU, ITS and RPB2 sequences into a 2,642-base-pair supermatrix, brought these threads together decisively.

The phylogenetic evidence is statistically robust. The Funiliomyces clade, comprising the type species, ten former Dactylaria species and the newly isolated Chinese strains, emerged as a well-supported lineage sister to the family Nothodactylariaceae, with support values of SH-aLRT 99.9 percent, ultrafast bootstrap 94 percent and Bayesian posterior probability 0.99. Crucially, the team went beyond tree topology and quantified genetic divergence. Using the Kimura 2-parameter model, they compared interfamily distances across all three loci. At the ITS locus, Funiliomycetaceae differs from its nearest family, Nothodactylariaceae, by 0.156 substitutions per site, a figure that still exceeds the smallest distance measured between any two established families in the order, 0.110 between Sporocadaceae and Beltraniaceae. The same pattern held for LSU and RPB2, providing convergent molecular evidence that this lineage deserves family rank.

Morphology backs the molecules. Funiliomycetaceae fits the general blueprint of Amphisphaeriales, with immersed perithecia and unitunicate asci bearing apical apparatuses that do not react with iodine, but its ascospores are diagnostic: fusiform, consistently two-septate, and bearing both apical and median appendages, a combination not found in any other family of the order. The asexual morphs show remarkable diversity in their conidiogenous cells, whose denticles range from large cylindrical or geniculate structures to entirely absent, in sharp contrast to the uniform pimple-like denticles of Nothodactylariaceae. Most species in the new family are saprobes, endophytes or epiphytes on a wide range of plant hosts, from acacias and beeches to grasses and conifers, spanning tropical to temperate regions across Asia, the Americas and Australia. With the addition, Amphisphaeriales now comprises 21 families.

Applying the One Fungus, One Name principle, the authors transferred ten species into Funiliomyces as new combinations: F. acaciae, F. bisepatus, F. calliandrae, F. fragilis, F. hwasunensis, F. mavisleverae, F. monticola, F. retrophylli, F. sparsus and F. zapatensis. The move unites sexual and asexual morphs that phylogeny shows belong to a single genus, even though only F. biseptatus is known from its teleomorph. To aid future identification, the study compiles a comprehensive table of asexual morphology, lifestyle, host associations and geographic distribution for all twelve species, a practical resource for researchers encountering these fungi on everything from Rhododendron leaves in Japan to decaying Nectandra foliage in Cuba.

The new species itself has an intriguing origin. Funiliomyces jiangxiensis was isolated from healthy roots of Tetradium ruticarpum, the medicinal plant known in Chinese as Wu Zhu Yu, whose fruits are used in traditional medicine for antitumor, cardiovascular protective, anti-inflammatory and antimicrobial effects. Collected in Jiangxi Province in 2022, the fungus produces narrowly fusoid-ellipsoid, zero- to three-septate conidia measuring 20 to 40 micrometers, and is distinguished from its closest relatives by shorter denticles than F. calliandrae and fewer conidial septa than F. hwasunensis. It is only the latest in a small but growing roster of endophytes described from this host, including Cyphellophora guangxiensis and Pseudokeissleriella tetradii, and the authors note that endophytes of medicinal plants are a recognized reservoir of bioactive compounds. A related species, F. hwasunensis, has already been shown to inhibit the growth of the rice pathogen Rhizoctonia solani by nearly 38 percent in dual culture.

What makes the study resonate beyond taxonomy is what it says about the hidden architecture of fungal diversity. A single morphological genus, defined by a spore-producing apparatus that evolved over and over again, concealed lineages separated by hundreds of millions of years and spread across six fungal classes. Only 31 Dactylaria species have ever been sequenced, and most were typed with a single gene, yet even that fragmentary data was enough to shatter the genus. The creation of Funiliomycetaceae resolves one branch of the puzzle and gives twelve species a coherent evolutionary home, but the type species Dactylaria purpurella still floats unplaced, and 100-plus named species await molecular scrutiny. For mycologists, the message is clear: the fungal tree of life is still being drawn, and every new isolate, especially from understudied hosts like medicinal plants, can redraw whole branches.

Subject of Research: Taxonomy and phylogenetics of the newly described fungal family Funiliomycetaceae within Amphisphaeriales

Article Title: Funiliomycetaceae fam. nov. ( Amphisphaeriales , Ascomycota ) accommodating Funiliomyces , including F. jiangxiensis sp. nov. from Tetradium ruticarpum and ten new combinations

Article References: Mi, L.-X., Hu, D.-M., Hyde, K. D., Eungwanichayapant, P. D., Mapook, A., Tennakoon, D. S., Zhang, J.-Y., & Song, H.-Y. (2026). Funiliomycetaceae fam. nov. (Amphisphaeriales, Ascomycota) accommodating Funiliomyces, including F. jiangxiensis sp. nov. from Tetradium ruticarpum and ten new combinations. IMA Fungus, 17, Article e179140. https://doi.org/10.3897/imafungus.17.179140

Image Credits: AI Generated

DOI: 10.3897/imafungus.17.179140

Keywords: Funiliomycetaceae, Dactylaria, Amphisphaeriales, Ascomycota, fungal taxonomy, phylogenetics, Funiliomyces jiangxiensis, endophytic fungi, Tetradium ruticarpum, new species, molecular systematics, medicinal plants