Philodendron ubigantupense Croat, sp. nov
TYPE: Panama. San Blas: on mainland opposite Isla Miria Ubigantupo, along trail to Digole, to 20 m, 9E26'N, 78E54'W, 19 July 1987, H. Herrera 294 (holotype, MO--3585503; isotype, PMA) .Figure 436.
Planta hemiepiphytica; internodia usque to 7.5 cm longa, 1 cm diam.; cataphylla decidua; petiolus subteres, 12--13 cm longus, in sicco 5--6 mm diam.; lamina oblonga, anguste cordulata basi, 27--32 cm longa, 8.5--9 cm lata, in sicco caniviridis; nervis lateralibus I obscuris; inflorescentia 1; pedunculus 8 cm longus, in sicco 5 mm diam.; spatha 9.3 cm longa, viridis; pistilla (7)8-locularia; loculi 1-ovulati.
Hemiepiphytic; stem scandent; internodes to 7.5 cm long, 1 cm diam., slender, drying 7 mm diam., gray-brown, irregularly and closely fissured, somewhat flaking; roots several per node, drying moderately smooth, reddish brown, semiglossy; cataphylls lanceolate, deciduous; petioles 12--13 cm long, drying 5--6 mm diam., subterete, drying dark gray-brown, minutely striate, sheathed to 1.5 cm; blades oblong, acuminate at apex (the acumen tightly inrolled, 5 mm long), narrowly cordulate at base, 27--32 cm long, 8.5--9 cm wide (3--3.8 times longer than wide), (2.2--2.5 times longer than petiole), about as long as petiole; upper surface dark green, drying weakly glossy, gray-green, lower surface slightly paler, semiglossy, drying greenish gray; sinus to 1.3 cm deep; midrib broadly convex above, convex and paler below, drying faintly striate; primary lateral veins almost totally obscure above and below; many minor veins, all free to base, arising from the midrib only, drying obscure above, close and weakly raised below, spreading at a 55--75E angle, more or straight to the margin.
INFLORESCENCES solitary; peduncle 8 cm long, drying 5 mm diam.; spathe green, 9.3 cm long, (1.2 times longer than peduncle); spathe tube weakly constricted, ca. 4.5 cm long; spadix bluntly pointed at apex, 10.8 cm long; pistillate portion 4 cm long in front, 3.7 cm long in back, 8 mm diam. at apex, drying 1 cm diam. at middle; staminate portion 8.1 cm long; fertile staminate portion 8.5 mm diam. at middle, 6.5 mm diam. ca. 1 cm from apex; sterile staminate portion 8 mm diam. at apex, 9 mm diam. at base; pistils 1.5 mm long; ovary (7)8-locular, 1.2 mm diam., with sub-basal placentation; locules 1.1 mm long, 0.2--0.3 mm diam.; ovule sac ca. 1 mm long; ovules 1 per locule, contained within transparent ovule sac, ca. 0.3 mm long; funicle ca. 0.3 mm long, (can be pulled free to base), style 0.9 mm diam., similar to style type D; style apex sloping to weakly rounded; style boss moderately broad and fairly pronounced; the androecium truncate, sometimes prismatic and weakly clavate, margins irregularly 4--5-sided, 0.8--1.5 mm long; thecae oblong, 0.2--0.3 mm wide, more or less parallel to one another; sterile staminate flowers clavate to prismatic, irregularly 4--5-sided, 1.3--1.7 mm long.
The flowering phenology of Philodendron ubigantupense is uncertain owing to its rarity, but since it has small inflorescences and was in flower in July, it probably both flowers and fruits in the wet season.
Philodendron ubigantupense is endemic to Panama, known only from the type locality along the Atlantic coast, at or near sea level in a Premontane wet forest life zone.
Philodendron ubigantupense is a member of P. sect. Calostigma subsect. Glossophyllum ser. Glossophyllum. This species is characterized by its scandent habit, long, slender internodes, subterete petioles and especially by its oblong, gray-green drying blades over twice as long as the petioles, weakly cordulate leaf bases, and almost totally obscure primary lateral veins.
Philodendron ubigantupense is perhaps most similar to P. folsomii, which has blades of similar size and color. The latter species differs in having short internodes and blades merely rounded at the base and with 8--10 distinct primary lateral veins. In addition, P. folsomii has 6--7 locules per ovary whereas P. ubigantupense has mostly 8 locules per ovary. Philodendron immixtum is another species that might be confused with P. ubigantupense, but it differs in having proportionately broader blades (to 2.8 times longer than broad) with up to five, obvious primary lateral veins.
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