Bakalin, V., Vilnet, A., Klimova, K. & Nguyen, V. S. 2019. Calypogeia vietnamica sp. nov. (Calypogeiaceae, Hepaticae) from North Vietnam and diversification in Calypogeia taxa with blue oil bodies. – Herzogia 32: 219 –229.

Calypogeia vietnamica is described from the northern fringes of mountainous Indochina. The species belongs to the peculiar group of Calypogeia with blue oil bodies that is taxonomically diverse in meta-Himalaya. The described taxon suggested as restrictedly distributed and may be the result of speciation occurred after Indian-Asian collision and movement of northern Indochina to southeast. The species occurs in moist rocky outcrops in the highest elevation of Indochina – Phan Xi Pang Mt. in the quite unique formation of ‘mossy’ Rhododendron forest resembling mossy forests occurring in humid tropics although different from the latter florogenetically. The collecting locality is characterized by high amount of received precipitation and common fog shrouds even in the dry season of Southeast Asian monsoon – a feature rarely observed in Indochina. The main characters of the taxon include exceptionally large and long decurrent, bilobed with prominently acuminate underleaves lobes and blue oil bodies. Illustrations and descriptions of the new taxon are provided, possible relationships are discussed.