Philodendron dodsonii Croat & Grayum, sp

Philodendron dodsonii Croat & Grayum, sp. nov.

TYPE: Ecuador. Pichincha: along Río Blanco across from Villa Hermosa on road 1.9 km N of main Sto. Domingo de Los Colorados--Esmeraldas Highway, departing main highway 25 km NW of Santo Domingo, 410 m, 0E5'S, 79E15'W, 13 Mar. 1992, Croat 72982 (holotype, MO--04658574--5; isotypes, AAU, B, COL, CR, K, M, MEXU, NY, PMA, QCA, QCNE, US. Figures 137--143, 150.

Planta hemiepiphytica; internodia brevia 2.5--3 cm diam.; cataphylla usque 20--33 cm longa, leniter vel acute 2-costata, interdum incostata, persistentia, demum fibrosa; petiolus subteres, 52--93 cm longus; lamina ovata, 36--87 cm longa, 28--66 cm lata, atriviridis supra, moderate pallidior et nitida infra, in sicco atriflavibrunnea et impolita vel leniter nitida; costa postica manifeste nuda; inflorescentia 2--5; pedunculus 5--9.5 cm longus, 6--10 mm diam.; spatha 16--18 cm longa; lamina spathae extus alba, intus rubella; tubo spathae extus rubropurpureo vel atrirubella vel viridi, intus rubro-purpureo vel atrirubello; pistilla (4)5-locularia; loculi ca. 20-ovulati.

Hemiepiphytic; stem appressed-climbing, leaf scars conspicuous, 1--2.7 cm long, 1.5--3.5 cm wide; internodes short on adults, stout, matte to glaucous, 2.5--3 cm diam., frequently longer than broad on nonflowering plants, gray-green, becoming whitish to grayish with age, epidermis flaking; cataphylls thin, spongy, to 20--33 cm long, weakly to sharply 2-ribbed, sometimes unribbed, light green, dark green-striate, persisting in parchment-like mats, eventually fibrous, rarely deciduous intact, margins clear; petioles 52-93 cm long, 9--25 mm diam., subterete to obtusely flattened abaxially, soft, drying black, surface pale, dull whitish-streaked, thinly dark green-striate, drying black; blades ovate, subcoriaceous, semiglossy, slightly bicolorous, very short acuminate to more or less acute at apex, weakly cordate to sagittate at base, 36--87 cm long, 28--66 cm wide (1.3--1.6 times longer than wide), (0.7--1.2 times longer than petiole), about equal in length to petiole, upper surface dark green, drying dark brown to dark yellow-brown, lower surface moderately paler and glossy, drying yellow-brown and matte to weakly glossy, margins weakly undulate and upturned, hyaline; anterior lobe 31--76 cm long, 39--70 cm wide, (1.65--2.9(4) times longer than posterior lobes); posterior lobes 11--29 cm long, 9-31 cm wide, broadly rounded to broadly obtuse; midrib flat to sunken, slightly paler than surface above, convex, concolorous below; basal veins 7--8 per side, and with the first free to base, numbers 3--7 coalesced 4--12 cm; posterior rib prominently naked to 6 cm along the sinus; primary lateral veins (4)7--8 per side, departing midrib at a 50--60E angle, to the margins, sunken and paler than surface above, convex to round-raised, usually darker than surface, sometimes paler than surface near base below; interprimary veins sunken and concolorous above, raised and concolorous below; tertiary veins visible, slightly darker than surface below; minor veins darker than surface, drying smooth below, arising from both the midrib and primary lateral veins.

INFLORESCENCES 2--5 per axil; peduncles 5--9.5(14) cm long, 6--10 mm diam., subterete, pale green, white-streaked; spathe 16--18 cm long ((1)1.8--3.5 times longer than peduncle), moderately constricted above the tube; spathe blade white outside, reddish inside; spathe tube red-purple to dark reddish (B & K red-purple 3/7.5) outside, red-purple to dark reddish inside, sap Mango-scented; spadix 13--15(18) cm long; pistillate portion 6 cm long in front, 5 cm long in back, 2.5 cm diam. at middle, 2.2 cm wide at base; staminate portion 11 cm long; fertile staminate portion ca. 1 cm diam.; sterile staminate portion 2.5--3 cm diam.; pistils 4 mm long,1.7--2.3 mm diam.; ovary (4)5-locular, with axile placentation; ovules ca. 20 per locule, 2-seriate, 0.3--0.4 mm long, slightly longer than funicle; funicle 0.2--0.4 mm long, adnate to lower part of partition, style similar to style type B; central style dome fairly well developed; style apex broadly domed; stigma inserted on entire style apex; the androeceium truncate, more or less prismatic, oblong, margins irregularly 4--5-sided, 1--2.5 mm long; thecae oblong, 0.3 mm wide, contiguous, more or less parallel to one another; sterile staminate flowers clavate, irregularly 3--5-sided, 2.3--3.7 mm wide.

Flowering in Philodendron dodsonii probably occurs during the rainy season, June--September, in Central America. It is known to flower only during September there, with post-anthesis collections also made from July through September and mature fruits in March. In South America, flowering collections have been made in June and July, post-anthesis from May through September, immature fruiting collections from February through November (except May, August, and October), and mature fruiting collections in September.

Philodendron dodsonii is known from Costa Rica, Colombia, and Ecuador and it expected to be found on the Caribbean slope of Panama. In Costa Rica, it occurs at 240 to 1300 m elevation, principally on the Atlantic slope but also on the Pacific slope on the Fila Costeña in Tropical wet forest and especially in Premontane rain forest life zones. In Ecuador, this species is known from Tropical wet forest life zones at 20 to 1750 m in Pichincha Province.

Philodendron dodsonii is a member of P. sect. Philodendron subsect. Philodendron ser. Fibrosa. This species is distinguished by its stout, short internodes, weakly two-ribbed cataphylls which persist in parchment-like mats and are eventually fibrous, more or less terete, petioles, large ovate, yellowish brown-drying blades with naked posterior ribs, and short-pedunculate spathes with the tube dark green to reddish outside and red within. Another feature useful for determination is the presence of tiny granulations or protuberances on the lower leaf surface. Juvenile blades often have minute pale dots on the surface.

Philodendron dodsonii is most easily confused with P. dominicalense, a species with very similar features which differs in having a single ovule per locule (versus ca. 20 for P. dodsonii) and an outer green spathe tube (versus red for P. dodsonii).

Philodendron dodsonii also appears close to P. schottianum, but that species differs in having cataphylls drying with a much thicker, yellowish epidermis and coarser fibers, petioles drying yellowish brown (versus almost black for P. dodsonii), blades drying with raised minor veins (versus essentially smooth for P. dodsonii) and inflorescences usually scarcely constricted above the tube.

Another species that might be confused with P. dodsonii is P. grayumii. It has blades similar in shape, size, and color upon drying but which differ in having the upper surface glossy upon drying and in usually having lacticifers visible on the lower surface, and especially in having mostly free basal veins with the posterior rib (when present) rarely naked

along the sinus.

A collection near San Vito and the only wild-collected specimen from the Pacific slope in Costa Rica differs in having longer internodes. It perhaps represents another species, but in other respects, it matches well with P. dodsonii.

This species was recognized as distinct by Sodiro (in herb.), under the name P. robustum Sodiro ined., previously published for a different species by Schott (1860).

Philodendron dodsonii is named in honor of Calaway Dodson, Director of Centro Científico Río Palenque and staff member of the Missouri Botanical Garden who first studied the species for the Flora of Río Palenque (Dodson & Gentry, 1978). The species was erroneously included in the above-mentioned work as P. devansayeanum L. Linden, a poorly known entity purportedly collected in the eastern Andes of Peru. Though the last-mentioned species was very poorly described and is represented by only a somewhat stylized painting (but no bona fide herbarium specimens), there is little liklihood that it could be the same as a species occurring on the western slopes of the Andes. The illustration appears to show leaf blades with basically free basal veins and little or no posterior ribs, whereas P. dodsonii has well developed posterior ribs. A collection from Ecuador in Sucumbios (Croat 50317) may prove to be this species. Though the inflorescence is immature its blades match those of P. dodsonii. Two other collections, Gentry 71004 from Bolivia (La Paz Province, 1500--1550 m) and Croat 55455 from Colombia (Cundinamarca Dept., 2000 m), may prove to be P. dodsonii. If so, the range statement could greatly become affected.

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COSTA RICA. Alajuela: Río Sarapiquí, at bridge on road to Colonia Virgen del Socorro, 830 m, 10E16'N, 84E11'W, Croat 68318 (CR, MO); 17 km NW of San Ramón, 785 m, 10E14'15"N, 84E33'W, Croat 68138 (MO); Río Cataratitas, ca. 20 km NW of San Ramón, 850 m, 10E12'30"N, 84E32'W, Grayum et al. 6327 (MO). Cartago: Río Reventazón, CATIE, Turrialba, ca. 600 m, 9E54'N, 83E39'W, Grayum et al. 3820 (MO); along Camino Raiz de Hule, SE of Platanillo (Tsipiri), 1200--1400 m, Croat 36796 (MO, US). Heredia: Zona Protectora La Selva, Río Peje--Río Guácimo, along Quebrada Cantarrana, 300--400 m, 10E22'N, 84E30'W, Grayum & Jacobs 3592 (CR, MO). Limón: Cordillera de Talamanca, along Río Madre de Dios, 240 m, 10E03'N, 83E26'W, Grayum et al. 8662 (MO); Río Blanco, Río Frio--Limón, W of Guápiles, Quebrada Danta, 3 mi. S of main highway, 360 m, 10E12'N, 83E49'W, Croat 68422 (CM, MO). Puntarenas: Las Cruces Botanical Garden, 1300 m, Croat 44420 (MO); 44464 (MO); ca. 4 km SE of San Vito, 1150 m, 8E47'30"N, 82E58'W, Grayum 8112 (INB, MO); Las Cruces Botanical Garden--Río Jaba, ca. 3.5 km SE of San Vito de Coto Brus, ca. 1160--1200 m, 8E47'30"N, 82E58'W, Grayum 5980 (MO). San José. San Isidro del General--Dominical, SW of San Isidro, 4.8 mi. from Río Pacuare, 1000 m, Croat 35260 (MO); 990--1100 m, Croat & Hannon 79114 (CR, INB, MO); Tarrazú, vic. Hormiguero, 1100--1200 m, Croat 78974 (CR, INB, MO).

COLOMBIA. Narino: Barbacoas, Reserva Natural Río Ñambí, 1325 m, 1E18'N, 78E08'W, Betancur et al. 4497 (COL, MO); Junin--Barbacoas, 18.1 km NE of Junin, 940 m, 1E21'N, 78E06'W, Croat 72454A (MO). Valle: Cali--Buenaventura Highway, 1.2 km E of Cisneros, 220--260 m, Croat 62829 (COL, MO, NY). ECUADOR. Cotopaxi: Quevedo--Latacunga, 3 km E of El Palmar, 800 m, Dodson & Gentry 10253 (MO); La Mana, 1 km N of Pucayacu, 750 m, Croat 73276 (MO); 2 km N of Pucayacu near Río San Francisco, 690 m, Croat 57080 (MO, QCA); Río Guapara, ca. 20 km NW El Corazón, 250 m, Sparre 17106 (S), 17164 (S), 17150 (S), 17108 (S), 17145 (S); Río Pilaló, Tenefuerste, km 52--53, 750--900 m, Dodson & Dodson 12914 (MO). Cotopaxi-Cañar-Chimborazo-Bolívar: Bucay, 1000--1250 ft., Camp E-3714 (MO, NY, S), E-3656 (MO, NY, S). Cañar: Azoques--El Triumfo Road, 1 km S of La Delicia, 2E27S, 79E10W, Croat 50867 (MO, QCA). El Oro: Piñas-Santa Rosa, above El Placer, 400--700 m, Harling et al. 15524 (GB); Machala-Loja Road, 890 m, Croat 50718 (MO, QCA). Esmeraldas: Quinindé, Bilsa Biological Station, Montañas de Mache, 35 km W of Quinindé, 5 km W of Sta. Isabela, 400--600 m, 0E21'N, 79E44'W, Pitman & Marsh 1146 (MO, QCA); Viche, Asplund 16514 (S); Fila de Bilsa, 7 km E of San José de Bilsa, ca. 80 km SW of Esmeraldas, 12 km SE of El Salto on Atacames--Muisne Road, 280 m, 0E37'N, 79E51'W, Gentry et al. 72977 (MO); Río Esmeraldas, opposite Quinindé (Rosa Zárate), Asplund 16361 (S); near San Mateo, 80 m, Croat 55632 (CAS, GH, MO, QCA); Río Lita, near Lita, 600--650 m, Croat 38944 (MO). Guayas: Teresita, 2 km W of Bucay, 270 m, Hitchcock 20537 (NY, US); 3 km W of Bucay, 270 m, Hitchcock 20489 (NY, US), 20440 (US); Cordillera Chongon--Colonche, 600 m, 1E48S, 80E47N, Cornejo & Bonifaz 5237 (GUAY, MO); Huigra-El Triumfo, 160 m, Croat 61593 (F, MO, QCA). Imbabura: 13--15 km E of Lita, 800 m, Croat 38918 (MO); Cachaco, 9 km E of Lita, 630 m, Croat 39000 (MO). Los Ríos: Babahoyo--Montalve, Hacienda Clementina, 20 m, Sparre 17966 (S); Centro Científico Río Palenque, 230 m, Croat 38651 (MO); 250 m, 50658 (MO, QCA); 220 m, 0E35'S, 79E12'W, 73803 (MO, QCA, US). Pichincha: Reserva ENDESA, Río Cabayales, ca. 700 m, 0E05'N, 79E02'W, Croat & Rodríguez 61503 (CAS, CR, MO, NY, QCA); 61516 (CM, MO, PMA, QCA, US); 710 m, 0E03'N, 79E07'W, Croat 73185 (CM, MO, QCA); Alóag-Santo Domingo, Río Toachi, 850 m, Sparre 17816 (S); Tinalandia, above Río Toachi, 700 m, Croat 55745 (MO), 55738 (MO, QCA, SEL); Nono-Nanegal, 13 km SE of Nanegal, 1440 m, Croat 38895 (MO); Nanegal, Sodiro 13 (G); 35 km NW of Santa Domingo, Río Blanco, ca. 250 m, Gentry 9619 (MO); Quito, Parroquia Nanegal, along Río Umachaca near Hacienda El Carmen, 1250 m, 0E07--7.5'N, 78E38'W, Webster et al. 28781 (DAV, MO); Reserva Maquipucuna, Hacienda Esparragos--Cerro de Sosa, ca. 6 km airline SE of Nanegal, 1500--1600 m, 0E7'N, 78E38'W, Webster & Bainard 27500 (DAV, MO); Cerro Campana, 5--6 km (airline) E of Nanegal, 1750 m, 0E09'N, 78E37'W, Webster et al. 30069 (DAV); La Independencia-Río Caoni, 210 m, Croat 55650 (MEXU, MO, QCA, WIS); Santo Domingo de Los Colorados, Hacienda Zaracay, 500 m, Sparre 15190 (S), 15191 (S), 15192 (S); Rancho Brahman, ca. 10 km NW of Santo Domingo de los Colorados on road to Esmeraldas, 400 m, Sparre 14090 (S); El Paraíso--Saguangal Road, 3 km from El Paraíso, 1500 m, 78E46'W, 0E10'N, Ollgaard et al. 37799 (QCA).