Article

The utilisation of citizen science initiatives has become an increasingly essential tool for biodiversity monitoring. Despite this, concerns persist regarding the quality and validation of the data collected. This study presents an approach to integrating citizen science observations with the expertise of bryophyte taxonomy, resulting in the identification of Asterella africana, a rare thalloid liverwort, at its northernmost distribution in Europe. The discovery was facilitated by a digital image submitted to iNaturalist and an identification key based solely on vegetative traits. This novel discovery serves to illustrate the significance of naturalistic social network in elucidating biodiversity patterns, even in the case of taxonomically challenging organisms that are possibly expanding in a warming climate.