PHILODENDRON AMPLISINUM
PROTOLOGUE: Philodendron amplisinum , published in Phytologia 60: 307 (1986). The protologue is reproduced below.
DISTRIBUTION: Venezuela (Zulia): Venezuela.
SPECIES DESCRIPTION:
Translated from protologue: Climbing herb. Stem up to 3 m long, 4–7 cm thick, with very short internodes, naked except toward the apex, where it is covered by the fibrous, dried remains of the cataphylls. Cataphyll 22 cm long. Petiole firm, subterete, ventrally angular-convex or flattened below, 65–98 cm long, 1.7 cm thick, black when dried, the sheathed portion 4–7 cm long, more or less geniculate for the distal 6 cm. Leaf blade chartaceous to subcoriaceous but fragile, broadly ovate in outline, 52–77 cm long, 46–57 cm wide; at the base with large, semicircular posterior lobes separated by a horseshoe-shaped or spathulate sinus 15–20 cm long and up to 11 cm wide, or rarely with the lobes overlapping and the sinus closed and obovate; at the apex broadly obtuse (100–140°), the tip itself acuminate (4–5 cm); dark brown when dried, the principal venation black; midrib 0.8 cm wide; first-order lateral veins 5(–6) on each side, arising from the midrib at 35–50°, the minor veins departing from the lower first-order lateral veins; the strong veins in each posterior lobe about 5, joined into a basal rib that is naked for 5–8.5 cm within the sinus.
INFLORESCENCE:
Translated from protologue: Inflorescences paired. Peduncle 16–18 cm long, marked near the apex with interrupted, pale, sometimes raised striations. Spathe 13–18 cm long, the tube 5.5–8.5 × 2.5–4.3 cm and dark green outside, the blade pale green outside. Spadix with the pistillate (fruiting) portion 6–7.3 × 2.5 cm, the sterile staminate portion 1.5 cm long, and the fertile staminate portion about equalling the pistillate portion. Pistillate flowers with a 3–5-locular ovary, the ovules numerous and superposed in each locule. Staminate flowers 4–5-androus. Berries 0.9 cm long.
ECOLOGY:
The type was collected along the shore of a small lagoon (lagunita) at 400–530 m elevation; the paratype was collected at 400–500 m elevation in partly cleared humid forest with abundant Sabal palms.
ETYMOLOGY:
Although the original description does not explicitly explain the name, the epithet combines the Latin ampli- (from amplus, “large” or “ample”) with sinus, “a bay or cleft,” and almost certainly refers to the conspicuously large, horseshoe-shaped sinus between the posterior lobes of the leaf blade, which reaches 15–20 cm long and up to 11 cm wide.
NOTES:
1. Type locality: the lower, northwest slopes of Cerro Negro, on the shore of a lagoon toward Lagunita Araguaney, southeast of the Río Guasare, Distrito Mara, Estado Zulia, Venezuela, at 400–530 m elevation. The holotype, Steyermark, Davidse & Stoddart 122689, was collected there on 28 May 1980 and is held at VEN.
2. Bunting assigned Philodendron amplisinum to Philodendron section Polyspermium Engl.
3. The plant shown in the original figure (Fig. 19) is the paratype, Bunting & León 12848 (NY, VZM), collected in December 1982 in humid forest of the Río Guasare basin.
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Philodendron amplisinum
2. Phytologia 60: 307 (1986) — protologue.