Philodendron squamicaule Croat & Grayum, Ann. Missouri Bot. Gard. 84(3): 529-531. (1997).
Hemiepiphytic; appressed-climbing, stem 3–20 cm long; internodes short, densely scaly with more or less deltoid, sometimes bifurcated scales, mixed with fewer acicular scales, drying reddish brown, 1–8 cm long, 2–3.5 cm diam., longer than broad, semiglossy, dark green, soon gray-green, finally tannish to brownish, drying straw-colored to reddish brown to brown, completely hidden by old cataphylls; roots few per node, slender, drying brownish; cataphylls fleshy, 27–34 cm long, unribbed to bluntly 2-ribbed, yellow-green, pink to reddish, or reddish brown, densely long-scaly throughout with a sparce underlayment of tuberculate structures, drying reddish brown, persisting as semi-intact pale fibers, sometimes with patches of epidermis, soon deciduous; margins folded in to form groove. Leaves erect-spreading; petioles 28–61 cm long, ca. 1 cm diam., erect-spreading, terete to subterete, purplish to dark brown, surface densely scaly, 1.5–4 mm long, flattened) with a sparse underlayment of tubercules; sheathing briefly only near the at base; petiolar scales of two types, short purplish scales deltoid or broader than high, less than 0.2 mm high, these interspersed with much longer, spreading light green acicular scales, 3–5 mm long, both types of scales drying reddish brown; blades ovate-triangular, thinly coriaceous to subcoriaceous, conspicuously bicolorous, short acuminate to acute at apex, sagittate-cordate at base, 26–53 cm long, 17.5–40 cm wide (1–1.5 times longer than wide), (0.7–1.1 times longer than petiole), broadest at the petiole attachment, margins hyaline, upper surface medium to dark green, semiglossy to sometimes almost matte above, slightly paler, light to silvery-green, glossy to semiglossy below, drying reddish brown on both surfaces; sometimes with sparse whitish raphide cells; anterior lobe 21–28 cm long, 18–26 cm wide (2.2–2.8 times longer than posterior lobes), margins straight to weakly concave; posterior lobes 8–10.7 cm long, 7.1–11.5 cm wide, directed toward the base to somewhat outward, broadly rounded; sinus parabolic to hippocrepiform on younger leaves, mitered on older leaves, 3.5–17 cm deep; midrib flat to sunken or deeply sunken and concolorous above, convex to broadly round-raised, concolorous to paler to light reddish below; basal veins 5–12 per side, with 0(1) free to base, third and higher order veins coalesced 2–6 cm long; posterior rib naked for 3–4.5 cm, densely scaly on both upper and lower edges; primary lateral veins 5–9 per side, departing midrib at a 30—45 degree angle (55 degree angle near base), moderately straight to the margins (the lowermost veins somewhat branched near the margins), deeply sunken and concolorous above, brown to reddish, round-raised and densely puberulent below; tertiary veins visible, slightly raised, darker than surface; minor veins moderately distinct below, arising from both the midrib and primary lateral veins; "cross-veins" sometimes moderately distinct on lower surfaces on drying. Inflorescences to 5 per axil; peduncle 3.5–8 cm long, olive-green, densely scaly, especially near apex, peduncle and spathe with scales of 2 lengths, both long and acicular, 1–2 mm long, much shorter and broader deltoid to tuberculate; spathe 15–17 cm long, 2–4.8 times longer than peduncle, moderately constricted above the tube, green, densely to sparsely scaly outside, shortly acuminate at apex; spathe blade sometimes greenish white outside, to 5.5 cm diam., light green, tinged red near base inside; spathe tube more or less ellipsoid, green, tinged red, covered with greenish scales (except for 5 mm along margin to 3 cm along infolded edge near base) outside, ca. 6 cm long, to 3.5 cm diam., reddish violet inside except greenish near tip inside; spadix 13.2 cm long; pistillate portion pale green to dirty-white, to 4.2 cm long in front, 3.6 cm long in back, 12 mm diam. at apex, 14 mm diam. at middle; staminate portion 11.5 cm long; fertile staminate portion 1.2 cm diam. at base, 1 cm diam. at middle, 7 mm diam. ca. 1 cm from apex; sterile staminate portion 1.2 cm diam.; pistils 1.22 mm diam.; ovary (3)4(5)-locular, with axile placentation; locules 1–1.2 mm long; ovules 20–28 per locule, arranged in one row or series of 2, ca. 0.2 mm long, longer than funicle; style similar to style type D; style apex flat; style boss narrow, fairly shallow; stigma hemispheroid, 0.7–0.8 mm diam., 0.2 mm high; the androecium prismatic, margins irregularly 4–6-sided, 1.4–1.6 mm long, 1.4–1.6 mm diam.; sterile staminate flowers prismatic, margins irregularly 4–6-sided, 1.1–1.2 mm diam. Infructescence with peduncle to 11 cm long, 8–11 mm diam.; spathe to 23 cm long, 1.7 cm diam., dark punctate in part and drying light brown inside; spathe tube 9–9.5 cm long, reddish, spathe blade to 14 cm long; spadix to 21 cm long; pistillate spadix 6–8.5 sm long, 3.2 cm wide; pistils 4.2 mm long, 2.7 mm diam.; locules to 3.3 mm long; fertile staminate spadix 11.5 cm long, 1.1 cm diam. midway; sterile staminate spadix 2.5 cm long, 1.4 cm diam.; staminate flowers to 3.3 mm long; berries white; seeds to 18 per locule, 1 mm long. Juvenile plants terrestrial, scandent; lower surface of blades purplish violet. Pre-adult plants with internodes 2–30 cm long, 0.5–1.2 cm diam.; petioles 8.5–18.5 cm long, 2-3 mm diam.; blades 14–28 cm long, 15–22 cm wide.
Type: Panama. Coclé: vic. El Copé, on western slope, just S of the old saw works area, 700 m, 8°38'N, 80°35'W, 12 July 1994, Croat & Zhu 76798 (holotype, MO-4613255--8; isotypes, B, CAS, CM,
COL, CR, F, G, K, MEXU, NY, PMA, US, VEN).
Esmeraldas: Lita--San Lorenzo road (based on Dodson 18645), cultivated at Río Palenque, Croat 73857 (MO); Lita-San Lorenzo, 18 km W of Río Lita bridge (old road), 6.6 km W of Río Chuchubi, 0°52'11"N, 78°27'16"W, 425 m, Croat et al. 82639 (MO).