Morphological and chemical studies of Hypogymnia from the Himalayas revealed one new species, three species new to the region, and a previously unrecognized synonym. Hypogymnia crystallina, distinguished by its rimmed holes in the lobe axils, a pruinose disc, POL+ epihymenium, and distinctive chemistry (zeorin, hypoprotocetraric acid, usnic acid and atranorin)...