Key to the species of Campyloneurum from Dept. La Paz, Bolivia
1. Rhizome diameter 3–5 mm; rhizome scales usually> 1.5 mm wide; 2–5 series of areoles between costa and margin. ............................................................................................................................................................. C. amphostenon
– Rhizome diameter 1–3 mm; rhizome scales usually <1.5 mm wide at the base; 1–3 series of areoles between costa and margin..................................................................................................................................................................... 2
2. Rhizome scales narrowly ovate without differentiated margins, with wide oblong cells, the cell lumina iridescent .... .................................................................................................................................................................. C. aglaolepis
– Rhizome scales linear-lanceolate with differentiated margins, with oblong or narrowly oblong cells, the cell lumina not iridescent. ................................................................................................................................................................ 3
3. Laminae shortly decurrent at the bases, abruptly ending in obtuse apices ................................................. C. poloense
– Laminae gradually ending in both ends, acute or acuminate....................................................................................... 4
4. Rhizome scale bases> 1 mm wide, scales brown in mass .................................................................. C. angustifolium
– Rhizome scale bases <1 mm wide, linear-lanceolate, scales dark brown in mass. ........................ C. angustipaleatum