Philodendron squamipetiolalum Croat, sp. nov.
TYPE: Panama. Code: Alto Calvario above El Cope, ca. 6 mi. N of El Cope, 710-800 m, 8¡39'N, 80¡36'W, 23 June 1994, Croat 68767 (holotype, MO-3591312^; isotypes, AAU, B, CAS, CM, COL, CR, DUKE, F, G, GH, HMNM, K, M, MEXU, NY, PMA, RSA, S, SCZ, TEX, US, VEN). Figures 375, 385-388.
Planta hemiepiphytica; internodia 3-17 cm longa, 6-15 mm diam., atriviridis, squamis approximatis, scalari-formibus, caespitosis, transverse orientibus; cataphylla usque 29 cm longa, incostata, squamala, persistentia nodis superioribus, mox decidua: petiolus 6÷16 cm longus, usque ca. 6 mm diam., teres; lamina ovata, rotundata ve1 subcordata basi, 15-37.5 cm longa, 9.5-29 cm lata; inflorescentia 1-2; pedunculus subteres, 6÷8 cm longus, dense squamatus; spatha 11-15.5 cm longa, 2-2.5 cm diam.; lumina spathae exius viridi. dense squamata, intus atrirubello, tubo spathae extus viridi, intus atrirubello; pistillaÊ 5-6-locularia; loculi 20-30-ovuli.
Appressed-climbing hemiepiphyte, occurring on understory trees in primary forest, fertile ca. 6 cm above the ground; stems trailing when juvenile, loosely appressed-climbing as adults; internodes 3÷ 17 urn lung, 6-15 mm diam., dark green, soon dark brown, drying yellow-brown, closely ridged-fissured with the surface moderately glossy, granular and with close, scalariform, tufted transversely oriented scales; cataphylls to 29 cm long, terete, unribbed, green and densely whitish scaly, promptly weathering to a loose semiorganized network of slender, pale fibers with fragments of epidermis, the fibers persisting at upper nodes, but soon completely deciduous; petioles erect to spreading, 6-16 cm long, to ca. 6 mm diam., terete, matte, dark green, surface densely covered with antrorse light green scales throughout (these ca. 6 mm long), densely granular-scurfy; blades somewhat pendent when young, spreading with petioles when mature, ovate, subcoriaceous, acuminate at apex, rounded to sub-cordate at base, 15÷37.5 cm long, 9.5÷29 cm wide (ca. 1.2÷2.1 times longer than wide), (1.6÷2.3 times longer than petiole), upper surface dark green, weakly glossy (subvelvety), drying dark brown, lower surface matte and much paler, drying yellow-brown; posterior lobes broadly rounded; sinus arcuate; midrib narrowly sunken and paler above, round-raised to thicker than broad, darker and densely puberulent below; basal veins 2-6(9) per side, with all free to base, or sometimes 3÷5 pairs coalesced up to 1.5 cm, posterior rib sometimes lacking; primary lateral veins 5÷7 per side, departing midrib at a 50÷55¡ angle, weakly quilt-sunken above, round-raised to thicker than broad, darker and densely puberulent below; minor veins flat but distinct and darker than surface below, some intermittent; "cross-veins" distinct, moderately raised on drying.
INFLORESCENCES 1-2 per axil; peduncle subterete, 6÷8 cm long, densely scaly; spathe 11÷15.5 cm long, 2÷2.5 cm diam. when furled, to 6.5 cm wide, and constricted somewhat when flattened, green outside, especially below, densely scaly (the scales whitish), deep reddish inside, especially in the tube; spadix yellowish white, 9.7÷13.5 cm long, to 1.3 cm diam., only weakly constricted midway; pistillate portion 2.7-4.7 cm long in the front, 0.7÷1.4 cm diam.; staminate portion 7÷8.8 cm long; fertile staminate portion broadest at upper one-third and bluntly pointed at apex, 6 mm diam. 1 cm from apex; sterile staminate portion 1.2 cm diam.; pistils 2.2 mm long; ovary 5-6-locular, ca. 1.4 mm long, with axile placentation, the sides covered throughout, especially toward apex, with short pale raphide cells; locules 1÷1.2 mm long; ovules 20÷30 per locule, 0.1÷0.2 mm long, oblong, arranged all along the length of the locules; style similar to style type B; short, 0.9÷1 mm diam., drying with 2÷5 depressions at apex; stigma 1÷1.1 mm diam. when flattened and dried. Infructescence not seen. Flowering in Philodendron squamipetiolatum occurs in the rainy season, during June in Central America. Ecuadorian collections at post-anthesis have been seen from February and April, with an early fruiting collection from August.
Philodendron squamipetiolatum ranges from Panama to Ecuador from sea level to 1300 m elevation in Premontane rain forest and Premontane wet forest transition to rainforest and Tropical rain forest. In Panama this species is known only from along the Continental Divide in Cocle Province, whereas in South America it occurs along the Pacific slope of the Andes.
Philodendron squamipetiolatum is a member of P. sect. Philodendron subsect. Achyropodium,. This species is distinguished by its long, inconspicuously scaly internodes; long, scaly, terete petioles (hence the name); long, scaly, deciduous cataphylls; rounded to subcordate blades with an arcuate sinus and puberulent major veins below; 1÷2 dark green, scaly inflorescences; and spathe tube reddish within.
In Central America, Philodendron squamipetiolatum is most easily confused with P. hammelii, a species with which it occurs in the vicinity of the type locality. Both species have small, ovate-cordate blades with scaly petioles and persistent, fibrous cataphylls. Philodendron hammelii is distinguished by having leaves drying grayish green above and yellowish brown below and closely arranged broad scales only near the apex of the petioles.
This species might also be confused with two others with scaly petioles. It is easily distinguished from both P. verrucosum, and P. squamicaule by its much smaller, subcordate vs. deeply cordate leaf bases, and from P. squamicaule by its more broadly ovate blades (vs. triangular ovate).
Madiwn & Besse 17185 from Esmeraldas Province, Ecuador, probably also belongs to this species, but field notes indicate that the stems are smooth. Unfortunately, there is no stem with the collection. It is not known whether the intent was to indicate that the stems lacked scales or whether it lacked other features. In addition, the stems were reported to be 10÷14 cm long and to 1.5 cm diam.