Philodendron dolichophyllum Croat, sp

Philodendron dolichophyllum Croat, sp. nov.

TYPE: Panama. San Blas: Nusagandi, El Llano-Cartí road, 9 mi. N of main highway, Nergan Igar (Nergan Trail), 350 m, 9E20'N, 79EW, 2 July 1994, Croat & Zhu 76569 (holotype, MO--4619523--25; isotypes, B, COL, CR, F, K, NY, PMA, US, VEN). Figures 145--148, 151.

Planta plerumque hemiepiphytica; internodia 4--6 cm longa, 2.5--4 cm diam.; cataphylla usque 20--60 cm longa, acute 2-costata, decidua; petiolus subteres, 28--41 cm longus, 7--20 cm diam.; lamina oblongo-lanceolata, anguste rotunda vel leniter subcordata basi, 53--75 cm longa, 12--15.2 cm lata, in sicco rubrobrunnea; nervis lateralibus I 17--20 utroque; inflorescentia 2--3; pedunculus 9--12.5 cm longus, 5--17 mm diam.; spatha 14--20 cm longa; lamina spathae extus viridi vel purpurescenti, intus albida; tubo spathae extus purpureo aut marronino, intus purpureo vel rubello; pistilla 6--8(9)-locularia; loculi 3--7-ovulati; baccae aurantiacae.

Hemiepiphytic, rarely terrestrial on steep banks; stem appressed-climbing, to 3 m long, elongate, leaf scars conspicuous, 1--1.4 cm long, 1--1.3 cm wide; roots few, dark yellow-green, faintly ridged, becoming reddish brown, semiglossy, to ca. 30 cm long, 3--4 mm diam.; internodes short, semiglossy, somewhat scurfy, 4--6 cm long, 2.5--4 cm diam., as long as broad or slightly longer than broad, dark green, drying brown; cataphylls coriaceous, 20--60 cm long, sharply 2-ribbed, pale greenish white, sometimes with reddish base, drying red-brown, deciduous.
LEAVES erect-spreading to spreading, the lowermost somewhat pendent; petioles 28--41 cm long, 7--20 mm diam., subterete, somewhat obtusely flattened adaxially, weakly glossy, moderately spongy, dark green to gray-green with a moderately conspicuous dark ring at apex, drying brownish; blades large oblong-lanceolate, subcoriaceous to weakly coriaceous, acuminate to gradually acuminate at apex, gradually tapered toward base or narrowly rounded to weakly subcordate at base, 53--75 cm long, 12--15.2 cm wide (4.4--4.9 times longer than wide), (1.6--2.3 times longer than petiole), broadest at or near middle, upper surface medium green, moderately bicolorous, drying reddish brown, semiglossy, lower surface semiglossy, paler; midrib raised to slightly convexly raised to broadly convex, paler than surface when fresh, drying darker than surface above, rounded, somewhat thicker than broad to acute, paler than surface below; basal veins lacking; primary lateral veins 17--20 per side, departing midrib at a 70--80E angle, slightly arcuate to margin, weakly sunken to moderately obscure above, weakly raised and paler than surface below; interprimary veins slightly less conspicuous than primary lateral veins; minor veins distinct, prominently visible below upon drying, arising from the midrib only. INFLORESCENCES 2--3 per axil; peduncle 9--12.5 cm long, 5--17 mm diam., medium green, minutely white striate, clearly demarcated from the colored spathe; spathe coriaceous, 14--20 cm long, (1.6--1.85 times longer than peduncle), acute at apex; spathe blade green to purplish outside, whitish inside; spathe tube oblong-ellipsoid, purple or maroon outside, purple to reddish inside; spadix sessile, (6)9.5--19 cm long, broadest near the base or above the middle; pistillate portion cylindrical to ellipsoid, 3.2--5.8 cm long, 1.1--1.5 cm diam. at apex, 1.1--1.7 cm diam. at middle, 1.1--1.2 cm wide at base, with 15--17 flowers visible per spiral; staminate portion 6--9.8 cm long; fertile staminate portion white, tapered to clavate, 8--11 mm diam. at base, 7--10 mm diam. at middle, 5--18 mm diam. ca. 1 cm from apex, narrower than or as broad as the pistillate portion; sterile staminate portion as broad as the pistillate portion, 8--11 mm diam.; pistils 1.4--3 mm long, 8--25 mm diam.; ovary 6--8(9)-locular, 9--25 mm diam., with sub-basal, sometimes basal placentation; ovule sac 0.5 mm long; ovules 3--7 per locule, contained within transparent ovule sac, 0.1--0.9 mm long, almost equal in length to funicle, style similar to style type B; style apex flat; stigma discoid, unlobed, 0.6--1.3 mm diam., 0.1--0.4 mm high, covering center of style apex; the androecium truncate, irregularly 4--6-sided, 0.4--0.8 mm diam. at apex; thecae ovate or oblong, 0.2 mm wide; sterile staminate flowers irregularly blunt, 1--2 mm long, 1 mm wide. INFRUCTESCENCE with berries orange, narrowly ovoid-ellipsoid, tapered and obscurely beaked at apex, 1.2 mm long, 9 mm diam.; seeds 2--3 per locule, 0.8--2.8 mm long, 0.2--2.5 mm diam.

Flowering and phenology in Philodendron dolichophyllum are unclear. Flowering collections have been made in February, June, and August, with post-anthesis collections from March, July, August, and October, and immature fruiting collections from March, June, July, and September.

Philodendron dolichophyllum is endemic to Panama (though to be expected in eastern Costa Rica), from 325 to 650 m elevation in Tropical wet forest life zones.

Philodendron dolichophyllum is a member of P. sect. Calostigma subsect. Glossophyllum ser. Glossophyllum. This species is distinguished by its appressed-climbing habit with at least the apical internodes short, sharply two-ribbed, deciduous cataphylls, subterete petioles (about half as long as the blade), and especially by its long, slender spreading leaf blades (hence the name "dolichophyllum"), which dry typically reddish brown and have weakly sunken primary lateral veins.

Philodendron dolichophyllum is not easily confused with any other species in Central America, but bears a superficial resemblance to P. pseudauriculatum with which it may occur. Both species have petioles and blades of comparatively equal lengths and spathes clearly demarcated from the peduncle. Philodendron pseudauriculatum differs in having proportionately much shorter leaves with blades which dry gray-green and have prominently sunken primary lateral veins. In addition, the outer surface of the spathe tube in P. dolichophyllum is typically maroon or purple, while the blade is green to purplish. Philodendron pseudauriculatum has the spathe tube white to pinkish white at anthesis.

Philodendron dolichophyllum might also be confused with P. auriculatum which differs in having proportionately longer petioles and blades drying mostly yellow-green and with a lower blade length/petiole ratio (1.4--1.6 versus 1.6--2.3 times longer than petiole) than P. dolichophyllum. In addition, the spathe of P. auriculatum is yellowish green outside and not clearly demarcated from the peduncle (clearly demarcated from peduncle in P. dolichophyllum).

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Additional specimens examined.

PANAMA. Bocas del Toro: Fortuna Dam area, road to Chiriquí Grande, N of Fortuna Dam, 650--700 m, 8E45'N, 82E15'W, McPherson 11136 (MO). Coclé: El Copé region, Alto Calvario, 200--400 m, 8E45'N, 80E35'W, Hamilton & Davidse 2638 (MO). Panamá: El Llano--Cartí, 10.1 mi. N highway, 325--350 m, 3E20'N, 78E58'W, Croat 67350 (F, MO, RSA, US); Mile 12, 200--500 m, Croat 22908 (F, DUKE, MO, NY); Mile 7, 460 m, 9E19'N, 79E59'W, Croat 75112 (MO); Km 18, 900--1000 ft., 9E16'N, 78E58'W, Sytsma 1068 (MO); ca. 16--18 km N, 400 m, Tyson & Nee 7359 (L, MO, QCA); El Llano--Cartí, near Nusagandi, 300--400 m, 9E20'N, 79'W, Hamilton & Stockwell 1075 (MO). San Blas: Nusagandi--Cartí, 400 m, 9E18'N, 78E58'W, McDonagh et al. 126 (BM, MO); El Llano-Cartí, 23--29 km N of Pan-American Hwy, 300--400 m, 9E22'N, 78E69'W, Knapp 1878 (M, MO, NY); Km 22, 350 m, 9E19'N, 78E55'W, de Nevers & Herrera 7849 (MO). Veraguas: Santa Fe region, Santa Fe--Río San Luis, past Escuela Agrícola Alto de Piedra, at Río Segundo Brazo, 480 m, 8E33'N, 81E08'W, Croat 66895 (CM, MO, PMA, SAR).