Morpho-molecular phylogenetic evidence confirms Natipusilla as a synonym of Ascominuta

This study investigates lignicolous freshwater fungi in Thailand, resulting in the collection of Ascominuta lignicola. Sequence data from the large subunit (LSU) and small subunit (SSU) ribosomal RNA genes revealed that A. lignicola is phylogenetically positioned within the Natipusilla clade (Natipusillaceae, Natipusillales). Morphologically, Ascominuta exhibits similarities to Natipusilla, characterised by small ascomata, few to absent pseudoparaphyses, subglobose asci, and predominantly one-septate ascospores surrounded by a gelatinous sheath if present. In accordance with the principle of priority, species previously classified under Natipusilla (N. bellaspora, N. decorospora, N. limonensis, and N. naponensis) were transferred to Ascominuta. This paper provides detailed descriptions and illustrations of Ascominuta lignicola, along with an updated phylogenetic backbone for the order Natipusillales.