Philodendron undulatum
Terrestrial, hemiepiphyte or epilith. Internodes 0.1-0.2 x 10-22 cm, stem covered with very long and lignified intravaginal squamules. Prophyll deciduous, 55-60 x 12-14 cm. Petioles slightly canaliculate adaxially, 43-63 x 0.8-1.2 cm. Leaf blade sagittate with shallowly pinnatifid margins, ovate in outline, 39-80 x 25-60 cm, chartaceous to slightly coriaceous, adaxial surface dark green, paler adaxially, anterior division 25-50 x 25-60 cm, apex acute to acuminate, secondary nerves 5-8 per side, arising at an angle of 40-85°, posterior divisions 11-24 x 12-27 cm, denuded portion of the basal rib 2-5 cm, acroscopic lobes 1-2, basiscopic 2-3. Inflorescences 1-3 per leaf axil, peduncle 15-30 x 0.8-1 cm; spathe white inside, green outside, 8-17 cm long; spadix 8-16 x 0.7-2 cm, fertile male portion tapering to the apex, 5-9 x 0.7-1.5 cm, sterile male portion 0.5 x 1-1.8 cm, female portion adnate up to 1/2 of its length, 3-5.5 x 1.3-2 cm. Male flowers 4-androus, stamens prismatic ca. 1 x 0.5 mm, staminodes clavate, 1-2 x 0.5 mm, gynoecium 1-2 x 0.5-1 mm, 7-8-locular, locules 2-3-ovuled, inserted near base, funicles ca. 1/2 of the ovule length. Berry not seen.
Philodendron undulatum occurs from Paraguay to Eastern Minas Gerais State, as a helophyte, epiphyte or epilithe. It is common in western limestone outcrops, usually growing directly on rocks or in soil pockets.