Philodendron niqueanum Croat, sp. nov.
TYPE: Panama. Darién: Serranía de Pirre, along headwaters of Río Escucha Ruido, ca. 16 km due N of Alto de Nique; ca. 7E47'N, 77E45'W, 27 July 1976, Croat 37942 (holotype, MO--2416709). Figures 293--296.
Planta hemiepiphytica; internodia brevia, usque 5 cm diam.; cataphylla incostata vel leniter 1-costata, rubra, persistentia plus minusve intacta; petiolus teres, (32)46--59 cm longus, in sicco 6--8 mm diam.; lamina ovata vel late ovata, (28)42--55.5 cm longa, (14)25--28.5 cm lata, circa tam longa quam petioles; sinus plus minusve V-formatus; inflorescentia immatura; pedunculus 4 cm longus; spathae viridis.
Hemipiphytic; stem scandent when young, appressed-climbing when adult; internodes short, to 5 cm diam., (younger stems with internodes to 8 cm long, 1.5 cm diam., epidermis moderately smooth, dark reddish brown; cataphylls unribbed to weakly 1-ribbed, red, persisting more or less intact; petioles (32)46--59 cm long, 6--8 mm diam., terete; blades ovate to broadly ovate, acuminate at apex, truncate to subcordate at base, (28)42--55.5 cm long, (14)25--28.5 cm wide (1.7--2 times longer than wide), (ca. 0.9 times the petiole length), about equal in length to petiole, upper surface weakly glossy, drying dark brown, lower surface paler, drying dark yellowish brown; anterior lobe (27)37--49.5 cm long, 25--28.5 cm wide (4.7--5.4(13.5) times longer than posterior lobes); posterior lobes (2)7--9 cm long, 9--12 cm wide, broadly rounded to obtuse; sinus more or less V-shaped, to 4 cm deep; midrib prominently raised, paler than surface above, raised below; basal veins 3 per side, with 0 free to base, some of the lowermost coalesced to ca. 1 cm; posterior rib never naked; primary lateral veins 5--9 per side, departing midrib at a 45--65(70E) angle, weakly arcuate to the margins, sunken above, raised below; minor veins obscurely visible, slightly raised on drying below, arising from the midrib only.
INFLORESCENCES immature; peduncle 4 cm long; spathe green, 7 cm long; spadix immature.
Flowering in Philodendron niqueanum is poorly known owing to too few collections overall. The species was collected with flower buds in late July and probably both flowers and fruits within the rainy season (although, since it flowers so late, the fruits may mature in the dry season).
Philodendron niqueanum is endemic to Panama, known only from the type locality on the Serranía de Pirre, at 1,530 to 1550 m elevation in Tropical Lower Montane wet forest.
Philodendron niqueanum is a member of P. sect. Calostigma subsect. Macrobelium ser. Ecordata. This species is characterized by its thick, short internodes, red, weakly one-ribbed cataphylls persisting mostly intact, terete petioles, and narrowly ovate, dark brown-drying blades about as long as the petioles.
Philodendron niqueanum is apparently close to P. lentii, which ranges from Costa Rica to Central Panama, but no further east than the province of Coclé. Both species are similar in having truncate- to subcordate-based leaf blades with more or less V-shaped sinuses. Philodendron lentii differs in having the primary lateral veins sunken, paler and much more conspicuous on the upper dried blade surface. In contrast, the primary lateral veins of P. niqueanum are scarcely or not at all paler than the surface on dried leaves and are raised rather than sunken. In addition, the epidermal pattern is alveolate and moderately smooth at 10x magnification on the upper blade surface of P. niqueanum, whereas P. lentii lacks an alveolate pattern and the adaxial surface is densely covered with round, pale inclusions.
Philodendron niqueanum is named for the type locality near the Alto de Nique, hence the name.
Additional specimen examined.
PANAMA. Darién: Cerro Pirre region, ca. 9 km from Alto de Nique, 1480--1520 m, Croat 37886 (MO, PMA, US).