SYNGONIUM CHOCOANUM

PROTOLOGUE: Syngonium chocoanum , published in Annals of the Missouri Botanical Garden 68: 590 (1982).

Syngonium chocoanum Croat, sp. nov. Planta hemiepiphytica; caudex ca. 2 cm diam., internodiis brevibus; lamina simplex; petiolus usque 5–6 cm e apice vaginatus; lamina anguste ovata, basi cordata; folia venis lateralibus utroque latere 9–15, infimis ramosis; venis tertiariis tenuibus, approximatis, obscuris. Inflorescentia ignota; spatha fructifer viridis, oblonga-elliptica, 8 cm longa. Type: Colombia, Chocó, Municipio of Nóvita, slope N of Cerro Torrá Filo ridge E of Río Surama, along trail to Alto del Oso, 500–600 m, Forero, Gentry, Sugden & Daly 3324 (COL, holotype; MO-2604930, isotype).

DISTRIBUTION: S. Panama to Ecuador (Esmeraldas): Colombia, Ecuador, Esmeraldas, Panama.

DISTRIBUTION NOTE: Colombia: Chocó, Nariño, Valle del Cauca Ecuador: Esmeraldas Panama: Darién, Panamá Province.

SPECIES DESCRIPTION:

Nomadic vine; appressed-climbing; stems ca. 2 cm diam.; internodes short, those on upper part of stem ca. 1 cm long; cataphylls thin, ca. 19 cm long, ca. 1 cm wide. Leaves with petioles to 43 cm long, narrowly sheathed to within 5 cm of apex, margins of sheath to 1 cm high, markedly broadened within 6 cm of base, acute and free-ending at apex (free part ca. 1.5 cm long, unsheathed part of petiole ca. 3 mm diam. (dried); blades entire, moderately thin, narrowly ovate, 26–36 cm long, 14–23 cm wide, acute or bluntly acuminate at apex, narrowed and cordate at base,, posterior lobes narrowly rounded; primary lateral veins 9–15 per side, arising at ca. 45–50º, straight or weakly curved to collective vein, with prominent branches (especially in lower half of blade) these curved and closely paralleling primary lateral veins; tertiary veins obscure (at least on drying), close, markedly parallel; collective veins 3, obscure, first ca. 5 mm from margin; basal veins 4 or 5 pairs, lowermost 3 or 4 basal veins coalesced ca. 5 mm before base.³

INFLORESCENCE:

Inflorescences 1–3 per axil; peduncle 9–11 cm long, to 14 cm long in fruit; flowering spathe 13–16 cm long; spathe tube 6–7 cm long, 1.7–2.0 cm wide uniformly green on both surfaces, the blade 10–11 cm long, greenish white outside, whitish inside; spadix 13.5 cm long in front, 12.5 cm long in rear, stipitate 1.6 cm; staminate portion 10.8 cm, 1.3 cm diam. midway, 7 mm diam. on constricted portion; sterile staminate portion 1.8 cm long, 1.2 cm diam.; pistillate portion pale yellow, 2.8 cm long, 1 cm diam. at base, 6 mm diam. at apex. Infructescences with peduncles to 11 cm long, 6 mm diam. (dried) midway, smooth, fruiting spathe tube narrowly elliptic, green, 8 cm long, 4 cm diam.; syncarp oblong-elliptic,4.5–5.5 cm long, 2.5–4.0 cm diam., tan. Flowers seen March, June, July; Fruits January, February, April.³

ECOLOGY:

Syngonium chocoanum ranges from southern Panama to Colombia (Chocó, Valle del Cauca & Nariño) and Ecuador (Esmeraldas) from sea level to 800 m in Tropical wet, Premontane wet and Tropical rain forest life zones.        .³ altitude: 0–800 m

ETYMOLOGY:

Named for the Chocó Department of western Colombia, where the type was collected on the slopes of Cerro Torrá in the municipality of Nóvita; Croat knew the species only from the southern Chocó when he described it.²

NOTES:

1. The species is a member of section Cordata and is characterized by its short internodes, long thin cataphylls, petioles narrowly sheathed to within 5 cm of apex with the sheath margins to 1 cm high and free-ending at apex, entire, simple, moderately thin, narrowly ovate-cordate blades with narrowly rounded posterior lobes, 9–15 primary lateral veins per side, 4 or 5 pairs of basal veins with the lowermost 3 or 4 basal veins coalesced ca. 5 mm before base as well as a moderately long pedunculate infructescences with a narrowly elliptic, green spathe. Sygonium chocoanum is most easily confused with Syngonium sagittatum from Mexico (northern Oaxaca) which differs by having a well-developed posterior rib usually more than 1 cm long, by having the posterior rib naked for some distance from the apex of the sinus and by having a longer spathe tube (usually 6.5–15.0 cm long at anthesis).³

REFERENCES:

1. Plants of the World Online, Royal Botanic Gardens, Kew — Syngonium chocoanum

2. Annals of the Missouri Botanical Garden 68: 590 (1982) — protologue.

3. Croat 2023. A revision of Syngonium Schott (Araceae-Caladieae) for Mexico, Central America, and the West Indies. Aroideana 46(2)

Additional photo from iNaturalist by dscherberich