Philodendron hebetatum Croat, sp

Philodendron hebetatum Croat, sp. nov.

TYPE: Panama. Coclé: vicinity el Valle de Antón, at forested flat area near Finca Macarenita at La Mesa, 800 m, 8E36'N, 80E07'W, 6 July 1994, Croat & Zhu 76693 (holotype, MO--4619514--15; isotypes, B, CAS, COL, CR, F, K, NY, PMA, US). Figures 33, 218--220, 225--226.

Planta hemiepiphytica; internodia 1--4 cm longa, 1.5--2.5 cm diam.; cataphylla ad 12 cm longa, incostata, persistentia semi-intacta; petiolus subteres, 27--75 cm longus, 8--18 mm diam., obtuse complanatus adaxialiter, in sicco conspicue flavibrunneus; lamina anguste ovato-triangularis, cordato-sagittata basi, 24--63 cm longa, 19--44 cm lata, atriviridi supra, opace albida, hebetata infra; inflorescentia 1--5; pedunculus 4--11 cm longus, 4--11 mm diam.; spatha 11--17.5 cm longa; lamina spathae extus viridi vel albida; tubo spathae extus atriviridi aut interdum purpureo vel violaceipurpureo vel rubro aut subroseo, intus albido vel rubello vel pallide violaceipurpureo; pistilla (4)5--8-locularia; loculi (4)20--24-ovulati.

Hemiepiphytic; stem appressed-climbing; internodes short, semiglossy, 1--4 cm long, 1.5--2.5 cm diam., longer than broad, green to gray-green, drying yellow-brown; roots moderately numerous per node, drying dark brown, ridged; cataphylls 12--35 cm long, unribbed, sometimes sharply 1-ribbed near apex (sharply 2-ribbed in South America), medium green, drying light to medium brown, persisting semi-intact at upper nodes, then deciduous with large patches of yellow-brown periderm remaining intact; petioles 27--75 cm long, 0.8--1.8 cm diam., more or less terete, obtusely flattened adaxially, spongy (in South America), dark green to gray-green, surface semiglossy to matte, transversely fissured near apex, drying pale yellow-brown.
LEAVES erect-spreading; blades ovate-triangular, subcoriaceous, abruptly acuminate at apeax, cordate-sagittate at base, 24--63 cm long, 19--44 cm wide (1.1--2.3 times longer than wide), (0.7--1.2 times longer than petiole), equal to or longer than petiole, margins concave, broadly undulate, upper surface semiglossy, dark green, drying conspicuously yellow-brown, semiglossy, lower surface opaque whitish, matte, paler; anterior lobe 19.5--49.5 cm long, 14.5--42 cm wide (1.9--3.6 times longer than posterior lobes); posterior lobes 7.1--20.2 cm long, 7.3--20.5 cm wide, obtuse to rounded; midrib broadly concave, paler than surface above, thicker than broad, weakly glossy, darker than surface below; basal veins 6 per side, with 1--2 free to base, second and third veins coalesced ca. 3 cm; posterior rib naked for 2.5--3.5 cm long; primary lateral veins 6--11 per side, departing midrib at a 35--50E angle, weakly sunken above, convex and darker than surface below; minor veins moderately distinct, fine, intermittent below, arising from both the midrib and primary lateral veins.

INFLORESCENCES 1--5 per axil; peduncle 4--11 cm long, 4--11 mm diam., white-lineate to coarsely white-streaked toward apex and on spathe base; spathe 11--17.5 cm long, 2--3.5 cm diam. (1.3--3.1 times longer than peduncle), white-speckled, semiglossy, constricted above the tube, 9--11 mm diam. at constriction; spathe blade green to whitish, somtimes rose-red outside, green to whitish or sometimes rose-red and white-speckled inside; spathe tube oblong-ellipsoid, 4--7 cm long, usually dark green or sometimes purple to violet-purple to red or pinkish outside, reddish to pale violet-purple (dark maroon=SoAm) inside; spadix white, cylindrical, 12.9--16.6 cm long, broadest near the base, constricted near the middle; pistillate portion whitish, cylindrical to ovoid, 3.8--8.9 cm long, 7--16 mm diam.; staminate portion 9.3--13.4 cm long; fertile staminate portion cylindrical, 8--13 mm diam., broadest at the base, narrower than pistillate and sterile portions; sterile staminate portion as broad as or narrower than the pistillate portion, 1--1.3 cm diam.; pistils glossy, 2.1--4(5.8) mm long, 1.2--2.6 mm diam.; ovary (4)5--8-locular, walls embedded with granular, crystal-like particles, locules 1.3--3.2(4.5) mm long, o.4--0.6 mm diam., with axile placentation; ovules (4)20--24 per locule, 2-seriate, 0.2 mm long, about equal in length to funicle; funicle 0.1 mm long, adnate to lower part of axillar wall, style 0.4--0.7 mm long, 1.2--2.6 mm diam., similar to style type B; style apex flat or rounded; stigma subdiscoid, 1--1.5 mm diam., 0.2--0.5 mm high, covering center of style apex; the androecium truncate, margins 4--6-sided, sometimes scalloped; thecae oblong, 0.3--0.4 mm wide, contiguous, more or less parallel to one another; sterile staminate flowers 3--6-sided, 1.5--2.5 mm long, 1.4--1.8 mm wide. Berries white, with purple stigmas; seeds 2-3,6,10--12,18--25 per locule, (1-5)8--11 mm long, 2--3 mm diam.

Flowering in Philodendron hebetatum apparently occurs throughout the dry season and first part of the rainy season in Panama, from December through July. Post-anthesis inflorescences have been collected from January through October (except September). Immature fruits have been collected in June and July. South American follow more or less the same pattern as those from Panama.

Philodendron hebetatum ranges from Panama to Colombia (Chocó) and Ecuador (Carchi, Esmeraldas, and Pichincha) along the Pacific coast, at 10 to 1880 m elevation in Premontane wet forest, Tropical wet forest and Premontane rain forest life zones. It is to be expected in adjacent Costa Rica. In Panama, most collections have been made at or less than 1400 m, rarely to about 1630 m.

Philodendron hebetatum is a member of P. sect. Philodendron subsect. Philodendron ser. Impolita. This species is characterized by its generally appressed-climbing hemiepiphytic habit, short internodes, usually unribbed, semi-intact persistent cataphylls with large patches of yellow-brown epidermis remaining intact, petioles equaling or exceeding the blade in length and drying conspicuously yellow-brown and smooth (thus clearly demarcated from the blade), and markedly bicolorous, narrowly ovate-triangular blades usually concave along the margin and matte and whitish on the lower surface.

The petioles of P. hebetatum are variable, being typically terete to obtusely D-shaped in Central America but sharply C-shaped to sharply D-shaped with acute to bluntly raised lateral margins in South America. South American populations also have the major leaf veins drying yellowish to pale red versus dark red in Central America. It is possible that the South American elements may ultimately prove to be at least subspecifically distinct.

Some South American specimens of P. hebetatum are particularly noteworthy. Holm-Nielsen et al. 25665, from Ecuador, differs from other collections in having the petiole epidermis drying paler yellow and the immature spathes drying a paler reddish brown. A collection from Nariño Department, Colombia (Croat 72425A) is unusual in having the margins of the anterior lobe markedly concave, but perhaps belongs also this species.

Philodendron hebetatum is easily confused, especially in live condition, with P. thalassicum, which may also have triangular-ovate blades much paler and matte on the lower surface. The latter differs, however, in having petioles which are sharply D-shaped and dry blackened rather than conspicuously yellow-brown. In addition, P. hebetatum has spathes reddish within, while in P. thalassicum they are greenish within.

Philodendron hebetatum is also similar to to P. strictum, which differs by its usually terrestrial habit, more or less reclining stems, and broadly ovate blades. Both species have pale, matte lower blade surfaces, yellow-brown drying petioles, and cataphylls with persistent patches of intact, yellowish brown epidermis. The lower blade surface in both species is covered with a wax-like substance, and dries with a fine reticulate pattern (areolate at 7x or higher magnification).

Philodendron strictum ranges from Costa Rica to Panama and Venezuela at 650 to 1900 m elevation. In Panama, where both species occur together along the Fortuna Dam Road, P. strictum tends to occur at higher elevations than P. hebetatum.

Juvenile plants (Croat 56049, 56174, 56213, 69291; Valle and Chocó Departments, Colombia) of P. hebetatum have oblong-elliptic leaf blades acute at the base but the petiolar epidermis already is colored as in adult plants. Leaves of older plants become increasingly rounder and broader at the base and finally subcordate to cordate.

An unusual collection is Croat 49298 from Chocó Department, Colombia, with leaves only shallowly cordate, even though they are in the upper end of the size range for adult plants of this species.

Sánchez et al. 553, a collection from Colombia (Antioquia) is noteworthy in being from 1880 m elevation and in being terrestrial. Holm-Nielsen et al. 25665 from Ecuador (Esmeraldas) differs from other South American collections in having paler, more flaky epidermis on the petioles and smaller, more or less sessile (perhaps immature) inflorescences. Perhaps it represents another species. South American collections of P. hebetatum differ from those of Panamanian material in that the petioles dry dark brown rather than yellowish.

Croat 61396 is unusual in apparently having only four ovules per locule.

Additional specimens examined.

PANAMA. Bocas del Toro: Fortuna Dam area, Chiriquí Grande--Fortuna, 2.8 mi. N of Divide, 850--950 m, ca. 8E45'N, 82E15'W, McPherson 9663 (MO, NY); 3.2 mi. N of Divide, 700 m, 8E45'N, 82E15'W, Croat & Grayum 60263 (CM, MO); 13.2 mi. W of Chiriquí Grande, 310 m, 8E45'N, 82E10'W, 60140 (AAU, MO). Chiriquí: Cerro Colorado, 18--27 mi. off Pan-American Highway along mining road, 1200--1500 m, Croat 33141 (MO); 1390--1410 m, Croat 37223 (MO); 9.2 mi. W of Chame, 1450--1480 m, 8E35'N, 81E50'W, Croat 69064 (CM, MO, PMA); 8.3 mi. beyond Chame, 1630 m, Croat 75042 (MO); 75046 (CM, MO); Fortuna Dam area, 4.5--5 km N of dam over Fortuna Lake, 1100--1135 m, 8E43'N, 82E07'W, Croat & Grayum 60073 (B, CM, MO); 11.8 mi. N of Los Planes de Hornito, Croat 48668 (MO). Coclé: El Copé region, 9.4 km above El Copé, 750--900 m, Croat 44686 (CAS, MO); Alto Calvario, 800 m, 8E39'N, 80E36'W, Croat 75075 (CM, MO); 710--800 m, 89E39'N, 80E36'W, Croat 68712 (ENCB, MO); El Valle region, vic. of La Mesa, N of El Valle de Antón, 900--1000 m, 8E37'N, 80E08'W, Croat 67279 (MO); 8E37'N, 80E07'W, McPherson 11203 (CM, M, MO); 8E40'N, 80E07'W, Knapp 5337 (MO); 5753 (MEXU, MO); La Mesa, 775 m, 8E36'N, 80E07'W, Croat 74783 (MO, QCA); 14372 (MO); 2000--2700 ft., Dwyer et al. 4567 (MO, NY); 860--900 m, Croat 37364 (MO); ca. 800 m, 25407 (MO); 800--900 m, 8E38'N, 80E09'W, 67204 (DUKE, MO, US). Darién: Parque Nacional Darién, near gold mine at headwaters of N branch of Río Pucuro, slopes of Cerro Tacarcuna, ca. 6 km N of Cerro Mali, 1300--1500 m, 8E09'5"N, 77E15'W, Hammel et al. 16541 (COL, MO); Río Tuquesa, Tyler Kittredge gold mine, ca. 2 air km from Continental Divide, Croat 27240 (MO). Panamá: Cerro Jefe region, vic. of summit, 850 m, 9E14'N, 79E22'W, Croat 67060 (MO, NY); 0.8 mi. beyond turnoff to Altos de Pacora, 770 m, 9E15'N, 79E29'W, Croat & Zhu 76611 (CM, K, M, MEXU, MO, W); 4.6 km beyond peak on road to Alto de Pacora, 26.3 km from InterAmerican Highway, 600 m, Croat 35934 (MO); 3--3.5 mi. NE of Altos de Pacora, 7.8--8.2 mi. above highway, 700--750 m, 9E15'N, 79E25'W, Croat 68661 (IBE, MO); 5--10 km NE of Altos de Pacora, 700--800 m, Mori & Kallunki 6031 (MO); El Llano--Cartí Road, Mile 10, near El Llano, 330 m, Croat 33773 (MO, US); Cerro Campana, ca. 850 m, 8E40'N, 79E50'W, Thompson 4598 (MO); Croat 17243 (MO), 780--875 m, 25224 (F, MO, PMA); 1000 m, Luteyn 3193 (DUKE); ca. 1 mi. from Inter-American Highway, ca. 150 m, Croat 35961 (F, MO); above Su Lin Motel, Croat 14726 (MO, PMA); lower slopes above FSU cabin, 850 m, Croat 22795A (MO). San Blas: El Llano--Cartí Road, Mile 14, 300 m, 9E15'N, 79EW, Croat 69231 (MO, PMA, SAR); sendero de Interpretación, 1 km al este del Campamento de los guardabosques de INRENARE, 800--900 m, 8E40'N, 79E55'W, Correa et al. 9489 (MO). Veraguas: Santa Fe region, Santa Fe--Río Calovébora, 0.6 mi. beyond Escuela Agrícola Alto Piedra, 735 m, Croat & Folsom 33996 (MO); Cerro Tute, 800--1100 m, 8E35'N, 81E5'W, Hamilton & Krager 3934 (MO); Río Tercero Braso Valley, beyond Escuela Agrícola Alto Piedra, above Santa Fe, Croat 27326 (MO).

COLOMBIA. Antioquia: Mpio. Frontino, Corregiento Nutibara, valley of the upper Río Cuevas, 1880 m, Sánchez et al. 553 (MEDEL); Río Anorí, confluence of Quebrada La Tirana and Río Anorí, ca. 3 km upriver from Planta Providencia, 28 km SW of Zaragoza, 400--700 m, Alverson et al. 299 (COL, WIS); Río Anorí valley near Planta Providencia, 350--600 m, 7E30'N, 74E50'W, Shepherd 924 (COL, WIS). Chocó: Quibdó--Tutunendo Road, ca. 3 km W of Tutunendo, 80 m, Gentry et al. 30108 (MO); 1 km E of Tutunendo, 100 m, 5E46'N, 76E35'W, Gentry et al. 30079 (COL); Medellín--Quibdó, Km 136.4, 63 km E of Tutunendo, 960 m, 5E47'N, 76E22'W, Croat 56348 (COL, JAUM, MO); Km 208.5, 9 km W of Tutunedo, <100 m, 5E39'N, 76E40'W, Croat 56213 (MO); Río Atrato, 39 km W of Bolívar, 1600 m, Croat 49261 (MO); 78 km W of Bolívar, 466 m, Croat 49298 (MO); 27 mi. W of Bolívar, 1190 m, 5E50'N, 76E16'W, Croat & Cogollo 52089 (MO); Quibdó--Bolívar, Km 137--138, 79--80 km E of Quibdó, 910--920 m, 5E45'N, 76E21'30"W, Croat 57345 (COL, JAUM, MO); Quibdó-Las Animas, ca. 1 km N of Las Animas, ca. 100 m, 5E14'N, 76E40'W, Croat 55958 (COL, MO); San José del Palmar--Cartago, Vereda La Bella between San José del Palmar and turnoff to El Cairo, 1430 m, 4E53'N, 76E13'W, Croat 56715 (COL, MO, QCA); Pueblo Rico (Risaralda)--Istmina (Chocó), Quebrada Antón, 15 km W of Santa Cecilia, 6 km W of Chocó-Risaralda border, 240--350 m, 5E20'30"N, 76E13'45"W, Croat 70961 (MO); Quibdó--Istmina, Km 4, <100 m, 6E28'N, 76E36'W, Croat & Cogollo 52234 (MO); Serranía de Baudo, Las Animas--Pato on Río Pato, ca. 150 m, 5E30'N, 76E46'W, Croat 56131 (COL, JAUM, MO, PMA); 16 km NW of junction with Quibdó--Istmina road near Las Animas, 100 m, 5E20'N, 76E42'W, Croat 56174 (COL, JAUM, MO); 5E16'N, 76E41'W, Croat 56049 (COL, JAUM, MO); Río San Juan, Docordó, 0 m, 4E15'N, 77E22'W, Forero et al. 4352 (MO). Nariño: along road between Junín and Barbacoas, 1.9 km NE of Junín, 1130 m, 1E21'N, 87E6'W, Croat 72425A (CM, MO). Risaralda: Mpio. Mistrato, Chirrincha, Río Aguita, 950 m, Franco et al. 3522 (MO); corregimientos de Geguadas--Puerto de Oro, 1550 m, Alonso et al. 9819 (MO); 9742 (MO). Valle: Bajo Calima area, Croat 62761 (CM, MO); ca. 15 km N of Buenaventura, Cartón de Colombia concession, Juanchaco region, 500 m, 3E56'N, 77E08'W, Gentry et al. 53711 (MO); Lijal--Gasolina road junction, SSW of San Isidro, 50 m, Gentry et al. 62926 (MO); 11 km N of main Cali--Buenaventura Highway, ca. 50 m, 3E56'30"N, 77E01'W, Croat & Monsalve 61396 (MO, QCA); Buenaventura--Río Calima, 33.3 km N of Cali--Buenaventura Highway, ca. 50 m, 4E02'N, 77E07'W, Croat 61279 (COL, MO, NY, TEX); Km 11, 50--80 m, 3E56'30"N, 77E01'W, Croat 69291 (CAS, F, L, MO, US); ca. 4 km from Río Calima, near Km 14 marker, <50 m, 3E56'N, 76E59'W, Croat 57530 (AAU, DUKE, K, MEXU, MO); Buenaventura--Málaga Road, 185 m, 3E56'N, 77E01'W, Croat 70103 (B, CAS, COL, F, K, MO, PMA, US); km 17.5, 130 m, 3E57'N, 77E01'W, Croat & Bay 75629 (MO); Km 18--20 on Cali--Buenaventura Highway, Finca Zingara, 1500--2000 m, Cabrera & van der Werff 15779 (MO); Río Cajambre, 5--80 m, Cuatrecasas 17054 (US); Río Naya, upriver from Puerto Merizalde, ca. 10 m, 3E15'N, 77E25'W, Gentry & Juncosa 40673 (MO). ECUADOR. Carchi: Tulcán Cantón, Reserva Indígena Awá, sector Sabalera, parroquia Tobar Donoso, 650--100 m, 1EN, 78E24'W, Tipaz et al. 1298 (MO); 1462 (MO). Esmeraldas: Lita--San Lorenzo, 15.5 km W of Lita, 705 m, 0E55'N, 78E28'W, Croat 72372 (MO); San José de Cayapas, 80 m, 0E52'N, 78E57'W, Holm-Nielsen et al. 25665 (AAU, MO); Eloy Alfaro, Reserva Ecológica Cotacachi--Cayapas, Charco Vicente, Río San Miguel, afluente del Río Cayapas, 150 m, 0E43'N, 78E53'W, Palacios & Tirado 11276 (MO, QCNE). Pichincha: Reserva ENDESA, Quito--Puerto Quito, Km 113, 0E05'N, 79E02'W, 750 m, Croat & Rodríguez 61454 (CM, K, M, MO, QCA); 61455 (K, MO, QCA); 710 m, 0E03'N, 79E07'W, Croat 73155 (AAU, B, COL, F, K, MO, NY, QCA, US).