Philodendron edenudatum Croat, sp

Philodendron edenudatum Croat, sp. nov.

TYPE: Panama. Veraguas: along road from Santa Fe to Río Calovébora, vic. of Alto Piedra, on Atlantic slope, 0.6 mi. N of Escuela Agrícola Alto Piedra (now Escuela Primer Agrícola Alto Piedra), 735 m, 4 Apr. 1976, Croat & Folsom 33988 (holotype, MO--2389069; isotypes, B, COL, CR, F, K, NY, US). Figures 156, 161--164.

Planta hemiepiphytica aut epiphytica; internodia 2.5--7.5 cm longa, 2--5 cm diam., viridia vel cana, in sicco pallide flavibrunnea; cataphylla 20--31 cm longa, acute 2-costata, decidua; petiolus subtere aut obtuse D-formatus, 34--41 cm longus, 1--1.5 cm diam., virens, guttatus purpureus; lamina ovata vel anguste ovata, cordata basi, 34--63 cm longa, 17--33 cm wide; costa postica haud nuda; inflorescentia 1; pedunculus 7--9 mm longus, 9--12 mm diam; spatha 10--13.5 cm longa; lamina spathae extus viridiflava, intus pallide viridi; tubo spathae extus atriviolaceopurpureo, intus atrimarronino; pistilla 7-locularia; loculi (3)4-ovulati.

Hemiepiphytic to epiphytic; appressed-climbing, leaf scars inconspicuous, 2 cm long, 2--2.5 cm wide; internodes moderately smooth and glossy, loosely and irregularly ribbed and grooved, 2.5--7.5 cm long, 2--5 cm diam., green to gray, soon brownish and more or less densely transversed-fissured to scurfy and glossy to semiglossy, drying pale yellowish brown; epidermis flaking; roots 1-few per node, reddish brown; cataphylls 20--31 cm long, D-shaped to sharply 2-ribbed, green, spotted with purple, persisting intact at upper nodes, eventually deciduous; petioles 34--41 cm long, 1--1.5 cm diam., subterete to obtusely flattened or obtusely D-shaped adaxially, especially toward toward apex, medium to dark green, surface densely pale lineate, purple spotted; sheathing up to 3/4 its length; blades ovate to narrowly ovate, subcoriaceous, semiglossy, moderately bicolorous, abruptly acuminate at apex, cordate to subcordate at base, 34--63 cm long, 17--33 cm wide (1.8--2.2 times longer than wide), longer than petiole, upper surface drying gray to gray-brown, lower surface drying yellow-brown; anterior lobe 29--51 cm long, margins convex; posterior lobes 6--17 cm long, 6--13 cm wide, directed downward; sinus arcuate to V-shaped or rarely parabolic, (4)6--12 cm deep; midrib flat to concave, paler than surface above, convex to narrowly rounded, maroon-spotted and darker than surface, drying paler than surface below; basal veins 3--4 per side, second and higher (or sometimes only third and fourth) coalesced 0.5--4.5 cm; posterior rib not at all naked; primary lateral veins 5--6 per side, departing midrib at a 60--75E angle, weakly curved to the gradually curved downward just before reaching the midrib, weakly sunken and paler above, convex and darker below; minor veins moderately distinct to more or less obscure, arising from both the midrib and primary lateral veins, drying minutely undulate. INFLORESCENCES 1 per axil; peduncle 7--9 mm long, 9--12 mm diam., more or less terete, light green, sometimes faintly tinged reddish medially on one side, clearly demarcated from spathe; spathe semiglossy, 10--13.5 cm long, 2--2.5 cm diam. midway, weakly constricted above the tube, oblong-ellipsoid, abruptly acuminate at apex (the acumen ca. 8 mm long); spathe blade greenish yellow outside, pale green, faintly striate inside, resin droplets forming on blade surface within; spathe tube 5 cm long, dark violet-purple with thin greenish margin (ca. 5 mm wide) and along a narrow band adaxially, faintly pale striate-speckled to faintly pale lineate outside, dark maroon inside; spadix sessile; gradually tapered to a blunt apex, 7.3--11.5 cm long; pistillate portion greenish, 4 cm long in front, 3.2 cm long in back, 1.2 cm diam.; staminate portion 7.3 cm long; fertile staminate portion 1.4 cm diam. at base, 1.1 cm diam. at middle, 8 mm diam. ca. 1 cm from apex, broadest at the base; sterile staminate portion 1.4 cm diam.; pistils 2.3 mm long; ovary 7-locular, 1.7 mm diam., with sub-basal placentation; ovules 3(4) per locule, contained within gelatinous matrix (no true envelope), 0.5 mm long; funicle 0.3 mm long (can be pulled free to base), style 1 mm diam., similar to style type B; style apex flat; stigma lobed, 1 mm diam., 0.2 mm high, covering apical depressions (forming a ring without papillae in the center of the apex), depressed medially; the androecium truncate, prismatic, irregularly 4--6-sided, mostly 4--5-sided, 0.9--1.2 mm long; sterile staminate flowers irregularly 4--5-sided, prismatic, 1.3--1.8 mm long.

Flowering in Philodendron edenudatum possibly occurs in the dry season based on a single, post-anthesis collection made in April.

Philodendron edenudatum is endemic to Panama, known in Premontane rain forest life zones at 110 to 1150 m elevation. It perhaps occurs in the adjacent Chocó of Colombia.

Philodendron edenudatum is a member of P. sect. Calostigma subsect. Macrobelium ser. Macrobelium. This species is characterized by its slightly elongate internodes, sharply 2-ribbed cataphylls, somewhat D-shaped, usually purple-spotted petioles shorter than the blades, and ovate leaf blades with maroon-spotted midribs and posterior ribs which are never naked, (hence the epithet "edenudatum," meaning not naked). Also characteristic are the solitary greenish inflorescences with the spathe tube dark purple-violet inside.

Philodendron edenudatum was first collected in 1979 at Alto de Piedra in Veraguas and more recently on Cerro Pirre in Darién.

The species appears closest to P. grayumii and is perhaps only subspecifically distinct from that species. The latter differs in having more regularly and conspicuously ridged dried stems with glossy, brownish yellow epidermis, petioles always longer than the blades (1.09--1.44 times longer), usually larger, more broadly ovate leaf blades (1.2--1.5 times longer than wide) with secretory ducts easily visible on the lower surface, and much larger inflorescences with ovaries having axile placentation (versus sub-basal in P. edenudatum).

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Additional specimens examined.

PANAMA. Darién: Parque National Cerro Pirre, W side, 550--760 m, 7E57'N, 77E46'W, Croat 68891 (CM, MO, PMA, US); 68901 (CM, MO); 68903 (MO); vic. of field station along Río Perisenico, 17 km N of El Real, 110 m, 8E01'N, 77E44'W, Croat & Zhu 77087 (MO, NY, US); 100 m, 77185 (CAS, CM, MEXU, MO, VEN); vic. Cerro Pirre, trail to Rancho Frío on slopes of Cerro Pirre, 200--450 m, 7E58'N, 77E43'W, Croat & Zhu 77157 (AAU, CM, MO, US); Serranía de Pirre above Cana Gold Mine, Río Cana--Río Escucha Ruido, 600--1000 m, Croat 37741 (MO). Veraguas: Santa Fe--Río Calovébora, 1.7 mi. past Escuela Agrícola Alto Piedra, 570 m, 8E38'N, 81E08'W, Croat & Zhu 76861 (CM, MO); trail to top of Cerro Tute, 1050--1150 m, Croat 48904 (MO); 48906 (MO, US).