Mora, M. & Croat, T. B.: Philodendron longirrhizum (Araceae), a new montane species from Colombia and Venezuela. — Willdenowia 37: 541–545. — ISSN 0511-9618; © 2007 BGBM Berlin-Dahlem. doi:10.3372/wi.37.37212 (available via http://dx.doi.org/)
Philodendron longirrhizum is described as a species new to science. It is known from the Western, Central and Eastern Cordillera in Colombia and from the Cordillera de Mérida in Venezuela, occurring in montane tropical forests at 1650 to 2500 m elevation. The species is a member of P. subg. Philodendron sect. Macrobelium subsect. Glossophyllum ser. Ovata. It is similar to and distinguished from P. montanum and P. fraternum.