Morphological Study and Distribution of Cyathus subglobisporus sp. nov. from Papanasam, Tirunelveli District, Tamil Nadu

Abstract

The genus Cyathus, commonly known as bird’s nest fungus, is recognized for its unique peridioles and cup-like fruiting bodies. In a recent mycological survey conducted in the Papanasam region of Tirunelveli District, Tamil Nadu, a novel species, Cyathus subglobisporus sp. nov., was discovered and is described herein based on its distinct morphological characteristics. The study aimed to document and analyze the morphological features and ecological distribution of this new taxon within the region’s forest ecosystems. Specimens were collected from decaying wood and leaf litter in semievergreen forest patches of the Western Ghats. Morphological examination was carried out using both stereo and compound microscopes. The fruiting bodies of C. subglobisporus are gregarious, with a dark brown, tomentose outer surface and a plicate inner wall. Peridioles are lenticular, attached to the peridium via funiculi, and are dark grey to black at maturity. The most distinguishing feature is its subglobose spores, measuring 8–9.5 × 7–8 μm, with a smooth surface—a key trait separating it from closely related species such as Cyathus stercoreus and C. olla. This study marks the first report of C. subglobisporus in the Tirunelveli region and contributes to the expanding fungal biodiversity records of the Southern Western Ghats. The occurrence of this species in undisturbed, moist forest habitats highlights the ecological significance of these microhabitats in supporting rare and novel fungi. Further exploration and conservation efforts are essential to understand the full extent of fungal diversity in the region, especially in light of increasing anthropogenic pressures.