SYNGONIUM BREWSTERENSE
PROTOLOGUE: Syngonium brewsterense , published in Novon 27: 56 (2019).
Syngonium brewsterense Croat & Delannay, sp. nov. It differs from Syngonium armigerum (Standl. & L. O. Williams) Croat in having larger leaves, with longer lobes and blades broadest across the tips of the posterior lobes, and much longer petioles. Type: Panama. Comarca Kunayala, Cerro Brewster, 09°18'N, 79°16'W, 800–850 m, 20 Nov. 1985, G. de Nevers, A. Henderson, H. Herrera, G. McPherson & L. Brako 6304 (holotype, MO-3320660!; isotypes, K!, PMA!).
DISTRIBUTION: Panama: Panama.
DISTRIBUTION NOTE: Panama: Comarca Kunayala.²
SPECIES DESCRIPTION:
Nomadic vine, appressed-climbing; internodes 1.7–4.0 cm, drying 0.7–1.7 cm diam., deeply acute-ribbed, yellow-brown. Leaves with petioles 21.5–45.5 cm, sheathed to within 2.0–3.3 cm from base of blade; free part drying sulcate; sheath erect, to ca. 6 mm high, somewhat free-ending, drying dark brown with sheath margins intact; blades narrowly sagittate-hastate, 27–35 cm long, 11.5–15.5 cm wide, (1.8)2.0–2.2 times longer than wide, broadest across tips of posterior lobes, acuminate at apex, 0.6–0.9 times as long as petioles, drying very thin and brittle, brownish and matte on upper surface, grayish yellow-green and semiglossy on lower surface; anterior lobe 22–28 cm long, 7–10 cm wide in lower 1/3, somewhat constricted at or slightly above petiolar plexus and 6.0–9.5 cm wide; posterior lobes 7.8–9.8 cm long, 3.2–4.0 cm wide across broadest part of lobe on auricle, narrowly rounded at apex, moderately auriculate on lower margin; sinus 4–6 cm deep, 1.7–2.3 cm wide above auricles, spathulate to subrhombic; primary lateral veins 5 or 6 per side, lowermost to 30°, upper ones to 50°– 60°; tertiary veins moderately distinct below, not markedly raised.³
INFLORESCENCE:
Inflorescences paired; peduncle 6–8 cm, 3–4 mm diam.; mature spathe 19 cm, spathe blade moderately coriaceous, persisting for a time on fruiting spadix; spadix ca. 17 cm long post-anthesis; staminate portion rotten, spathe tube 8–9 cm, 4.3–4.6 cm diam., green outside, red inside. Infructescences with syncarp 6.0–7.5 cm; seeds gray, 6–7 mm long, 3.5–4.0 mm diam., ovoid to ellipsoid. Fruiting in late November.³
ECOLOGY:
Syngonium brewsterense is endemic to Panama, known only from the type locality on Cerro Brewster in Comarca Kunayala at 800–850 m in a Premontane rain forest life zone.³ altitude: 800–850 m
ETYMOLOGY:
Named for Cerro Brewster, the mountain in Panama's Kuna Yala comarca on which the type was collected at 800–850 m. The Latinized ending-ense means "from that place."³
NOTES:
1. The species is a member of section Cordata and is characterized by its deeply acute-ribbed, yellow-brown internodes, petioles sheathed to near the base of blade with a somewhat free-ending, intact sheath, the narrowly sagittate-hastate acuminate blades which are shorter than the petioles and dry very thin and brittle, brownish and matte on upper surface, grayish yellow-green and semiglossy on lower surface and are somewhat constricted near the petiolar plexus, the posterior lobes moderately auriculate on lower margin as well as by the spathulate to subrhombic sinus, the paired, moderately short-pedunculate inflorescences with a large, moderately coriaceous, green spathe tube (red on inside) with gray-seeded berries. The species is most similar to Syngonium hastiferum from Costa Rica which differs by having its leaf blades narrowly ovate-elliptic and scarcely or not at all constricted at the base of the anterior lobe with a sinus that is very narrow at the apex then flaring out, as well as by its 3 or 4 pairs of basal veins and about 13 primary lateral veins per side. The sterile collection of Syngonium brewsterense (Croat & Grayum 59733) was included by Grayum as Syngonium castroi in his treatment of Syngonium for the Manual de Plantas de Costa Rica⁴ based on its leaf shape and proximity to the type.³
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Syngonium brewsterense
2. Novon 27: 56 (2019) — protologue.