International Aroid Society

15. Syngonium angustatum Schott, Oesterr. Bot. Z. 8:175. 1858. TYPE: Nicaragua, Chontales, Punta Poderoso, Oersted (C).

S. oerstedianum Schott, Oesterr. Bot. Z. 8:178. 1858. TYPE: Costa Rica, Guanacaste, Oersted (not seen); Schott drawing 3214 (NYBG photo 4332).
S. albolineatum hort., H. G., Bull's Catalogue p. 6. 1871. LECTOTYPE: N. E. Brown, Feb. 27, 1877.0 (Specimen from the type plant of Hort. Bull) (K).
S. podophyllum Schott var. albolineatum (Hort.) Engler, Pflanzenr. IV.23E (Heft 71):129. 1920.
S. podophyllum var. oerstedianum (Schott) Engler, Pflanzenr. IV.23E (Heft 71): 129. 1920. Nepthytis triphylla hort. Nash ex L. H. Bailey, in Cycl. Amer. Hort. 3:1076. 1901. TYPE: (not seen, fide Birdsey, 1955).
Syngonium gracilis Matuda, Anales Inst. Biol. Univ. Nac. Mexico 43, Ser. Bot. 1:56-57. 1972, non (Miq.) Schott. TYPE: Mexico, Oaxaca, Palomares, Juehitan, near Rio Coatzacoalcos, 200 m, MacDougall 804-4 (MEXU, holotype).

Juvenile plants with stems not glaucous, usually sparsely muricate; petioles sheathed usually less than Vs their length; blades dark green, marked on the upper surface along the principal veins with gray green, cordate, less than 6 cm long, the anterior lobe ovate, the posterior lobes suborbicular; intermediate leaves sagittate or hastate, acuminate at the apex. Adult stems not glaucous, sparsely muricate; internodes mostly 2-10 cm long on the flowering stems; petioles sometimes pruinose, sheathed 1/2-4/5 their length, 15-40 cm long; blades pedatisect, dark green above, sometimes grayish green on the midrib and rarely on the lateral veins; leaflets 3-11, usually conspicuously free from one another, the lowermost auriculate, the median leaflet elliptic to oblong-elliptic to oblanceolate, acuminate at the apex, attenuate, acute or cuneate at the base, 11-31 cm long, 4-10 cm wide, the rachis gradually curved, the lateral leaflets inequilateral, the inner margin acute to cuneate, the outer margin rounded to auriculate, the auricle rounded to bluntly acute, rarely slightly pinched off; primary lateral veins 3-5 pairs, sunken above, raised beneath; tertiary veins distinct.
Inflorescences to ca. 7 per axil;
peduncles glaucous, almost 3-sided, 5-10 cm long, and erect at anthesis, to 17 cm long and pendent in fruit; spathe 7 to 14 cm long; spathe tube elliptic, 2-5 cm long, 1.0-2.5 cm diam., green and usually glaucous outside, green inside; spathe blade cream on both surfaces, 6-9 cm long, 1.5-3.5 cm wide, acuminate at the apex; pistillate portion of the spadix 1.3-2.6 cm long, 5-10 mm diam., greenish, the flowers irregularly hexagonal, the stigma discoid; staminate portion 2.5-6.5 cm long, 5-15 mm diam., pale yellow, the flowers completely fused into a syn-andrium with no sign of fusion, the apex conspicuously refuse.
Infructescences usually bright red, sometimes reddish orange, sometimes glaucous; fruiting spadix brown, 2.5-4.5 cm long, 1.5-2.5 cm diam. Figs. 32, 40, 45.

DISTRIBUTION: Syngonium angustatum ranges from Mexico (southern Tamaulipas) through Belize, Guatemala, Honduras and Nicaragua to northern Costa Rica. It is cultivated in Panama. Although most abundant at lower elevations, it ranges up to 700 m (to 1000 m, fide Birdsey, 1955). The species is most abundant in tropical moist forest life zones, but has been collected in tropical dry forest in Nicaragua and Costa Rica.
Syngonium angustatum is closest to S. podophyllum but can usually be distinguished by its more uniformly slender leaflets, the papillae of the older stems, and the deeply retuse, fused staminate flowers (also see the key). According to Birdsey (1955) the species hybridizes with S. podophyllum in Mexico.
Syngonium angustatum apparently flowers most abundantly during the early rainy season with some flowering during the dry season as well.

BAHAMAS: Eleuthera, CorreII 49000 (NY).
BELIZE: Maskall Pine Ridge, Gentle 1144 (F, G, MICH, NY). BELIZE: Northern Highway, Dwyer & Liesner 12043 (GH, MO, NY); SW of Belize, O'Neill 8257, 8542 (MICH). CAYO: S of Grano de Oro, Croat 23403 (F, MO), 23781 (MO), Dwyer 10890 (MO); Roaring Creek, Wiley 246 (MO); Near Augustine, Spellman 1584 (MO). COROZAL: Between Corozal and Pachacen, Gentile 62 (F), Lundell 4935 (F, NY); No other location, Gentle 459, 616, 502 (MICH). STANN CREEK: W of Stann Creek, Croat 24205 (MO). TOLEDO: N of Columbia Forest Station, Croat 24232 (MO); Punta Gorda, Croat 24469 (F, MO); Temash River, Dwyer 12885, (MO).
COLOMBIA: Island of Providencia, Proctor 3476 (US).
COSTA RICA: ALAJUELA: Vicinity of Los Chiles, Holm & Iltis 812 (A). GUANACASTE: S ofPenas Blancas, Liesner 4658 (MO).
GUATEMALA: ALTA VERAPAZ: Eastern portions, Watson & Sereno 104 (GH); E ofPanzos, Croat 41699 (MO). IZABAL: SW of Puerto Barrios, Croat 41836 (MO), Standley 72127, 72565 (F). PETEN:
Uaxactun, Bartlett 12664 (MICH, US); La Libertad, Lundell 2432 (MEXU, MICH), 2544 (GH), 3213 (F); National Park of Tikal, Ortiz. 333 (F). ZACAPA: N from Route CA9, Croat 41882 (MO).
HONDURAS: COLON: W of Trujillo, Murry 449 (MO); Vicinity of Cuidad de Castilla, Nelson & Martinez. 1191 (TEFH). CORTES: SW of Omoa, Croat 42559 (MO); Road to Chamelecon Cafradia, Molina 3849 (GH, F); SW of Puerto Cortes, Nelson et al. 3020 (TEFH). GRACIAS A DIOS: Mosquitia, Clewell & Cruz. 4050 (GH, MO); Puerto Lempira, Nelson 4846 (TEFH). OLANCHO: Dulce Nombre de Culmi, Nelson & Clewell 438 (MO, TEFH).
MEXICO: No other location, Sandoval 6 (US). CAMPECHE: Tuxpena, Lundell 815 (F, MICH, US). CHIAPAS: Vicinity of Palenque, Croat 40137, 40315 (MO), Matuda 3825 (GH, MICH, MEXU). OAXACA: N ofMatias Romero, R. M. King 841 (MICH, US); Palomares, MacDougall 804A (MEXU);
Tuxtepec, Sousa 1859 (MEXU). PUEBLA: Forest of Ajeujihe, D. R. Canta 520 (MEXU). SAN LUIS POTOSI: Tamazunchale, M. T. Edwards 581 (MO). TABASCO: Villahermosa, Bunting 1652 (BH, MO), Spellman et al. 115 (MO). VERACRUZ: San Andres Tuxtia, Dressier & Jones 16 (GH); Vicinity Juan Rodnguez Clara, Gomez-Pompa & V aides 1727 (MO); Vicinity Sayula San Juan Evangelista, Leija & Garw 8137 (MEXU); Tampico, Nevling & Gomez-Pompa 426 (MEXU); Vicinity Camp Hnos, Valdiva 1184 (JALAPA, MEXU). YUCATAN: Chichen Itza, Steer 1629 (MICH); Izamal, Greenman 452 (F).
NETHERLANDS ANTILLES: Bonaire, Arnoldo 2296 (US).
NICARAGUA: BOACA: N of Rio Las Canas, Stevens 5848 (MO); Vicinity Rio Quilan Bridge, Slevens 9323 (MO). CARAZO: Near Jinotepe, Standley 8576 (F). CHONTALES: La Libertad, Standley 8904 (F), Stevens 4091, 4092, 4204 (MO); Road to Cuapa, Stevens 3654, 6470 (MO). GRANADA: Volcan Mobacho, Atwood & Neill AN90 (MO). MANAGUA: Vicinity of National School of Agriculture, Seymour & Atwood 2228 (MO); Tipitapa, Atwood & Seymour 3424 (GH, NY, UC), Croat 39051 (MO), Gamier 774 (US), Neill 7260 (MO), Stevens 9509 (MO). MATAGALPA: Summit of El Toma Road, Neill 1572 (MO); Between La Danta and La Luna, Stevens 9573 (MO). NUEVA SEGOVIA: N of Jalapa, Neill 1608 (MO). RIVAS: Isia de Ometepe, Stevens 6640 (MO). ZELAYA: Near Bluefields, Hamblett 613 (MO); SE of Cerro San Isidro, Proctor, Jones & Facey 27048 (NY); Along Cano Majagua, Stevens 6983 (MO); Vicinity of San Jose del Hormiguero, Stevens 7006, 7047 (MO); Near Tala Has and Puente Mango, Stevens 7639 (MO); SW of Rio Wawa, Stevens 7924 (MO).
PANAMA: CANAL ZONE: Stevens Circle, Balboa, Croat 9181 (MO); Summit Gardens, Croat 17059 (MO).
THAILAND: BANGKOK: Cultivated at Kasetsart University Nursery, Nicolson 1691 (B).