Philodendron alticola Croat & Grayum, sp

Philodendron alticola Croat & Grayum, sp. nov.

TYPE: Panama.Chiriquí; Parque La Amistad, 3.5 mi. W of Cerro Punta, 2 kminside park along old abandoned roads and trails, 800 m, 8E53'N, 82E35'W, 28 Mar. 1993, Croat 74906 (holotype, MO--4343624--5; isotypes, B, CR, F, K, PMA, US). Figures45--48.

Planta epiphytica aut hemiepiphytica; internodia (1.5--2)4--10 cm longa, 2--4 cm diam., in sicco pallide flavibrunnea, subtiliter costata; cataphylla usque 28 cm longa, incostata, in sicco pallide brunnea, decidua; petiolus 42--70 cm longus, 7--10 mm diam.; lamina ovato-sagittata, 44--72 cm longa, 21--44 cm lata, sagittata basi, in sicco brunnea supra, flavibrunnea infra; inflorescentia 1--2; pedunculus 5--12 cm longus; spatha 11.5--14(18) cm longa, viridis; pistilla (4)5--6(7)-locularia; loculi 12--18-ovulati.

Epiphytic or hemiepiphytic; stem appressed-climbing; internodes dark green, promptly gray-green, finally light brown, semiglossy, finely ribbed, (1.5--2)4--10 cm long, 2--4 cm diam., drying pale yellow-brown, epidermis sometimes loosening and flaking free in small patches; cataphylls sharply D-shaped with weakly raised margins, pale green, weakly glossy, drying thin, to 28 cm long, unribbed, drying pale brown, deciduous at lower nodes, persisting semi-intact at upper nodes with a few exposed pale fibers, in part persisting as pale fibers at lower nodes with a few pale fibers and small, thin fragments of pale brown epidermis.
LEAVES erect-spreading to spreading; petioles 42--70 cm long, 7--10 mm diam., subterete, medium green, weakly glossy, faintly lineate, obtusely flattened adaxially, weakly spongy, drying greenish to blackened, slightly flattened toward the apex adaxially, surface drying more or less matte, sometimes with portions of epidermis loose and bubbled, tan and translucent; sheathing subtending an inflorescence, to 6 cm long; blades narrowly ovate-sagittate, subcoriaceous to moderately coriaceous, semiglossy, somewhat bicolorous, weakly and shortly acuminate at apex, sagittate at base, 44--72 cm long, 21--44 cm wide (1.6--2 times longer than wide), (about as long as petioles), broadest somewhat above point of petiole attachment, upper surface dark green, matte, drying brown to greenish brown and almost matte, lower surface moderately paler and weakly glossy, drying yellow-brown; anterior lobe 34--35.5 cm long, margins convex; posterior lobes 13--26 cm long, 11--17 cm wide, directed downward; sinus obovate, 10--19 cm deep; midrib speckled, slightly paler, drying broadly convex, concolorous above, narrowly rounded, slightly paler, drying prominently convex, often flat and irregularly ridged, yellowish brown below; basal veins 5--6 per side, with the first free to base, the second coalesced 1--5 cm, third and higher order veins coalesced 4--7.5 cm long; posterior rib naked for 1--3 cm; primary lateral veins 5--8 per side, those near end of blade departing midrib at a 50--65E angle, those in the lower one-half of blade departing at 80--95E angle, broadly curved to the margins, obtusely sunken and slightly paler, drying weakly raised above, convex and paler than surface, splayed out and downturned at the midrib, drying weakly raised below; interprimary veins inconspicuous; minor veins moderately distinct, fine, arising from both the midrib and primary lateral veins, drying prominulous, alternating with secretory canals appearing as intermittent lines, sometimes branched, blackened and minutely sunken.

INFLORESCENCES erect, 1--2 per axil; peduncle more or less terete, coarsely striate (coarser on spathe and base of tube, pale short-lineate otherwise), weaker toward apex, 5--12 cm long, drying 7--10 mm diam., pale green, drying dark brown; spathe coriaceous, 11.5--14(18) cm long, scarcely or not at all constricted midway, green to yellowish green throughout, acuminate; spathe blade dark green throughout, drying dark brown and unmarked, smooth outside, pale greenish white to white on upper two-thirds of blade inside; spathe tube 2.8--4 cm long, 2--3 cm diam., red to to red-violet to purplish on lower one-third of tube inside, spadix 9-14 cm long; pistillate portion pale green, 0.8--1.2 cm long, 1--1.5 cm diam. throughout; staminate portion 8--12.5 cm long; fertile staminate portion creamy white, stubby, evenly and bluntly tapered to apex, 1.5--2 cm diam. throughout, broadest at the base, much broader than the pistillate portion; sterile staminate portion 1.5 cm diam.; pistils 3--4 mm long, 1.7--1.8 mm diam., ovary (4)5--6(7)-locular, with axile placentation; ovules 12--18 per locule, 2-seriate, weakly translucent, 0.4--0.5 mm long, longer than funicle; funicle 0.1--0.2 mm long, adnate to lower part of partition, style similar to style type B; central style dome sometimes weakly developed; dried style base raised but flattened apically with a narrow, pale ring around its outer margin; stylar canals emerging as tiny funnels at base of small apical depressions and arranged separately in a ring, drying as minute funnels extending above the surface of the style boss; style apex weakly concave; central domes and small depressions surrounding stylar canal exits; stigma covering entire style apex; androecium truncate, oblong prismatic, margins irregularly 4--5-sided or 4--6-sided, 0.9--1 mm long; thecae more or less oblong, ca. 0.3 mm wide; sterile staminate flowers in part prismatic, in part weakly clavate or irregularly 4--6-sided, 1.2--1.8 mm wide. INFRUCTESCENCE in early fruit to 14 cm long; spathe becoming dark brown with paler lines in tube; berries white with dried style bases ca. 2 mm long, brown, with a narrow smooth ring around its margin; seeds tan, ovoid, weakly mammiliform, 1.4--1.8 mm long, 1--1.2 mm diam.

Flowering in Philodendron alticola is documented by just a few collections and might be bimodal. Specimens in Panama were collected both in bud and immature fruit in February (nearly mid-dry season in Panama), but post-anthesis collections were also made in August and September. No mature fruits were seen. The region where P. alticola occurs is decidedly less seasonal (at least in terms of totally rainless days) than is much of the rest of Panama. This might induce a less seasonal flowering in Philodendron.

Philodendron alticola is known only from eastern Costa Rica and western Panama in the region adjacent to the frontier at 800 to 2500 m elevation in Tropical Lower Montane wet or possibly Lower Montain rain forest. It is one of the most high-ranging species of Philodendron subg. Philodendron Schott in Central America, hence the name "alticola" (meaning high-dweller).

Philodendron alticola is a member of P. sect. Philodendron subsect. Philodendron ser. Fibrosa. In addition to the high elevations at which it occurs, the species is characterized by having the internodes longer than broad and drying yellowish brown and finely ribbed, by its subterete petioles about twice as long as the blades, drying darkened and sometimes with bubbly epidermis, the ovate-sagittate blades which dry mostly dark brown above and yellowish green below with conspicuous blackened, interrupted and sometimes branched secretory ducts as well as by the usually paired, short-pedunculate inflorescences with the spathe scarcely constricted above the tube, green outside, white inside on the blade and red to purple on the tube within. The species is most similar to P. straminicaule, which is also subscandent and has similarly colored blades. That species differs in lacking prominent intermittent laticifers and the fertile staminate portion of the spadix constricted above the sterile portion, the sterile staminate portion of the spadix only slightly thicker than the pistillate portion, and a doughnut-shaped style with the style tubes in the bottom of a concavity upon drying. In addition, it has only 1 ovule per locule (versus 12--18 per locule for P. alticola). In contrast, P. alticola has conspicuous laticifers, the staminate spadix scarcely or not at all constricted above the sterile portion and the sterile portion of the spadix much thicker than the sterile staminate portion. The dried style base of P. alticola is flat at the apex with erect, tubular-extensioned stylar pores.

The species is also similar to P. schottianum H. Wendl. ex Schott, which also shares the conspicuous latex canals on the lower blade surface and a similarly stubby spadix but that species differs in having shorter internodes, cataphylls which persist as a dense mass of fibers (versus semi-intact or as only a few pale fibers interspersed with small fragments of epidermis in P. alticola), by its petioles which dry smoother and more matte and by its more broadly ovate blades which often have conspicuous cross-veins.

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Additional specimens examined.

COSTA RICA. Limón: Cordillera de Talamanca, Atlantic slope, Valle de Silencio, along Río Terbi, 0.5--1.5 airline km W of Costa Rican-Panamanian border, 2300--2400 m, 9E8'N, 82E57'W, Davidse et al. 28735 (CR, MO); S side of unnamed cordillera between Río Terbi and Río Siní, 2--4 airline km W of Costa Rican--Panamanian border, 2300--2500 m, 9E9-11'N, 82E57-58'W, Davidse et al. 28931 (MO). PANAMA. Chiriquí: vic. of Las Nubes, 2.7 mi. NW of Río Chiriquí Viejo, W of Cerro Punta, 2200 m, Liesner 323 (MO, US), 325 (MO, US); Cerro Punta, Las Nubes, 2000 m, Croat 26492 (MO).