Trachyodontium, a New Genus of the Pottiaceae (Musci) from Ecuador

Abstract

Trachyodontium zanderi Steere, gen. et sp. nov., is described as a new taxon. It differs from Leptodontium in the bordered leaf margins and the spiculose peristome teeth, but resembles it in the large size, the lanceolate, recurved leaves, and the long-sheathing perichaetial leaves. As far as is known, it is restricted to a single river valley in Ecuador, where it is relatively abundant. As Richard Spruce (1908) noted during his ex- plorations of South America (1849-1864) over a century ago, Ecuador has an amazingly rich bryo- phyte flora. Although Spruce was speaking of the then vast Canelos forest in the drainage of the Rio Pastaza (alt. 300-1,000 m), his conclusions are equally true at higher elevations. In addition to its unique morphological features, the genus Trachy- odontium is also remarkable for its geographical iso- lation in Ecuador. To date, in spite of an increasing tempo of botanical and bryological exploration, it is still known only from a single valley on the south slope of Volcin Pichincha, where it is reasonably abundant locally and produces sporophytes in quan- tity, namely the valley of the Rio El Cinto below the village of Lloa.