A new species of Holomitrium (Musci: Dicranaceae) from South America, and a key to Holomitrium in the northern and central Andes of South America

Holomitrium azuayensis differs from all other species of Holomitrium known from South America, Central America, and the Caribbean by its completely entire leaf margins. Holomitrium xol-ocotzianum H. A. Crum from Mexico is a similar species that has entire leaf margins below, but the leaves are toothed at the apex. It is a much smaller plant with shorter leaves that have a cucullate apex. Also similar is H. pulchellum Mitten from Central America and northern South America. It has sub-entire or weakly crenulate to sometimes serrate leaf margins, but it has more slender and erect leaves than H. azuayensis. The alar region in H. pulchelum is only weakly differentiated, and often fugacious, which also distinguishes it from H. azuayensis. This new moss species is currently known from Ecuador.