Philodendron davidsonii Croat, subsp. davidsonii
Internodes 1--5 cm long, 3--8 cm diam.; cataphylls 38--54 cm long, sharply 2-ribbed; petioles 56--85 cm long, obtusely V-shaped, broadly sulcate adaxially, with adaxial margins sharp, with a dark ring at apex; blades 49.5--67 cm long, 21--43 cm wide; basal veins 3--6, mostly 4 per side, with 1--2 free to base, 4th to 6th veins coalesced 3--4 cm; posterior rib 0.8--4 cm long, not at all naked to 4 cm; primary lateral veins (16)18--21 per side, departing midrib at 65--75E angle. INFLORESCENCES 1--3 per axil; peduncle (3.5)5--9 cm long, flowers with style similar to style type D; style apex usually flat with a broad style boss bearing a medial divot; stigma subdiscoid to globular, weakly lobed. Berries greenish, nearly ripe.
Flowering in Philodendron davidsonii subsp. davidsonii occurs in the late dry season and early wet season with post-anthesis collections from March through August (except April) and immature fruiting collections from in June and November. Cultivated collections at the Missouri Botanical Garden flowered in April, May, June, and July.
Philodendron davidsonii subsp. davidsonii ranges from northeastern Costa Rica (no doubt into southeastern Nicaragua as well) to Panama on the Atlantic slope, from near sea level to about 100 m elevation in Premontane wet forest and Tropical wet forest life zones. No specimens have been seen in Costa Rica above 100 m elevation.
Additional specimens examined for P. davidsonii subsp. davidsonii.
COSTA RICA. Heredia: La Selva Field Station, ca. 100 m, Jacobs 2708 (MO), Grayum 2931 (MO), 2829 (MO). Limón: Hacienda Tapezco--Hacienda La Suerte, 29 air km W of Tortuguero, 40 m, 10E30'N, 83E47'W, Davidson 3956 (CM, F, MO); 7097 (L, MO, RSA), 8782 (MO); Manzanillo de Talamanca, ca. 5 m, 9E38'N, 82E39'W, Grayum & Burton 4326 (MO); Refugio Barra del Colorado, between Río Chirripocito and Río Sardina, 12 m, 10E38'N, 83E45'W, Grayum 9807 (CR, MO). PANAMA. Bocas del Toro: Fortuna Dam--Chiriquí Grande, 10 mi. below the divide off highway 1.2 mi., 300--400 ft., Kress et al. 86-1992 (MO, SEL).