SYNGONIUM STANDLEYANUM
PROTOLOGUE: Syngonium standleyanum , published in Baileya 14: 21 (1966).
Syngonium Standleyanum Bunting, sp. nov. ? Syngonium triphyllum 'Lancetilla' Hort. in A. B. Graf's Exotica 3: 228, 234, 1723. 1963. Folia stirpium juvenilium simplicia; lamina integra, elliptica, inaequilateralis, ad apicem basimque acuminata, ad 16 cm. longa et 6.7 cm. lata; petiolus longe vaginatus, laminae subaequalis. Foliarum intermediarum lamina elliptica vel oblonga vel lanceolata, ad basim cordata, vel basim versus angustata illinc abrupte auriculata vel subhastata, lobis 2 basalibus brevibus angustis oblongis gradatim majoribus in foliis deinceps prodeuntibus. Foliorum stirpium adultarum lamina usque ad basim tripartita, haud nitida, lobo medio valde inaequilaterali elliptico vel oblongo, ad 28 cm. longo et 12 cm. lato, ad apicem basimque acuminato, costa in superficie canaliculata, nervis lateralibus primariis numerosis supra profunde insculptis, infra valde prominentibus (badiis in folio siccato), demum cum nervo connectivo a margine ca. 1 cm. remoto conjunctis, lobis lateralibus elliptico-oblongis, ad 24 cm. longis et ad 7.7 cm. latis (sed plerumque pro longitudine angustioribus), valde inaequilateralibus (latere externo quam interno duplo latiore), ansatis, ad apicem obtusis, latere interno ad basim acuto-cuneato, latere externo ad basim rotundato et obtuso, costulae basi nuda ad 1.5 cm. longa; petiolus ad 35 cm. longus, anguste vaginatus sub 9 cm. infra apicem, vagina foliae inflorescentiam subtendentis latiore, parte summa adaxialiter acute angulata. Pedunculus ca. 4.5 cm. longus; spatha ca. 11.5 cm. longa, tubo viridi ca. 5 cm. longo fusiformi-cylindrico, lamina alba expansa ca. 6.5 cm. longa, acuminata, quam spadice ca. 2.7 cm. longiore. Holotype: P. C. Standley & Juvenal Valerio 45248, El Arenal, Guanacaste, Costa Rica, elev. 485–800 m, 18–19 Jan 1926, epiphytic vine in wet forest, spathe green, the upper part white (US).
DISTRIBUTION: Belize to Costa Rica: Belize, Costa Rica, Honduras, Nicaragua.
DISTRIBUTION NOTE: Belize: Belize, Toledo Costa Rica: Alajuela, Guanacaste, Heredia, Limón Nicaragua: South Caribbean Coast.
SPECIES DESCRIPTION:
Nomadic vine to 5 m; juvenile plants with scandent stems, not glaucous; sap clear; internodes 2.3–6.5 cm long; petioles sheathed more than 4/5 their length, 4–12 cm long; blades elliptic, inequilaterally acuminate at apex, 4–10 cm long, 2–4 cm wide; intermediate leaves elliptic to oblong or lanceolate, sub-hastate or cordate at base. Adult plants appressed-climbing, stems green, not glaucous, densely and minutely papillate, drying pale brown with longitudinal wrinkles; internodes 3–12 cm long, less than 1 cm diam. Leaves with petioles (15)25–35 cm long, sheathed 2/3 or nearly full length (l.5–9.0 cm from apex), portion above sheath acutely angled on upper side; blades trisect, leaflets free; median leaflet slightly to very inequilateral, elliptic to oblong, (13)18–28 cm long, 6.5–15.0 cm wide, acuminate and mucronate at apex, acute and attenuate at base; lateral leaflets elliptic-oblong, 11–24 cm long, generally less than 70% as long as the medial lobe, acute-cuneate on inner edge at base, obtuse to rounded or slightly auricled on outer edge at base; petiolule 5–15 mm long; primary lateral veins ca. 6 per side, sunken above, raised beneath; smaller veins clearly visible (at least on drying).³
INFLORESCENCE:
Inflorescences 1–4(5); peduncle 4.5–5.2 cm long, less than 4 cm diam. on drying; spathe 10.0–11.5 cm long; tube green, 4.5–5.0 cm long, ca. 3 cm diam., fusiform-cylindroid; spathe blade white, ovate-elliptic, 6.2–7.0 cm long, ca. 2.5 cm diam. (closed), ca. 3.5 cm wide (open), acuminate at apex, 2.8 cm longer than spadix; spadix 8.1–9.0 cm long; staminate portion of spadix clavate, creamy white, 6.0–7.5 cm long, 1.1 cm diam. on fertile section, 0.5 cm on constricted segment; sterile staminate portion 1 cm long, 0.7 cm diam.; pistillate portion 1.5 cm long. 0.5 cm diam. Infructescences with spathe blade bright red-orange inside, yellowish green outside except red-orange at very base; berries white (Davidse 36582). Flowers January, June-August Fruits June–August.³
ECOLOGY:
Syngonium standleyanum ranges from Belize and Honduras to Costa Rica on the Caribbean slope. In Costa Rica, it occurs in Tropical wet forest and Premontane wet forest life zones, generally in secondary forests at elevations from near sea level (50 m) to 700 m.³ altitude: 0–700 m
ETYMOLOGY:
Named for Paul C. Standley (1884–1963), the American botanist whose collections underpin the floras of Mexico and Central America. The type was collected by Standley at El Arenal in Guanacaste Province, Costa Rica.³
NOTES:
1. The species is a member of sect. Syngonium and is characterized by its non-glaucous, densely and minutely papillate internodes, petioles sheathed 2/3 or nearly throughout, trisect blades with the leaflets free and petiolulate, the lateral leaflets less than 70% as long as the medial lobe, about 6 primary lateral veins per side, up to 5 inflorescences, a fusiforme green tube and the infructescences with the spathe blade bright red-orange inside with white berries. Bunting (1966) reported that the species could be distinguished by the matte upper blade surfaces, deeply impressed primary lateral veins, and the shape of the leaf blade. The species is close to Syngonium triphyllum which differs by having white to yellow sap, blackish drying leaf blades and petioles which are sheathed more than 70% of their length in contrast to having clear sap, greenish drying leaf blades and petioles sheathed less than 70% their length. The species is perhaps closest to Syngonium. mauroanum but that species lacks densely papillate stems, usually has more prominently hastate posterior lobes, and occurs in Tropical moist forest or Premontane moist forest life zones.³
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Syngonium standleyanum
2. Baileya 14: 21 (1966) — protologue.