Leucocasia gigantea (Blume) Schott

CATE Araceae, 17 Dec 2011. araceae.e-monocot.org

Distribution

Native from southern China and Indochina to West Malesia. In Malesia: Malay Peninsula, Sumatera and Java; absent from Borneo. Sastrapradja & Hambali (1979) note the occurrence of this species in Kalimantan, but we have not seen any material from Borneo, where Alocasia robusta may be confused with it.

General Description

Very robust herb, c. 150–250 cm tall, solitary to clump-forming; Stem condensed, creeping, c. 10 cm diam., lacking stolons. LEAVES several together; petiole to 150 cm long, light green with conspicuous to somewhat obscure waxy-white-glaucous coating, sheathing in the lower c. 1/3–1/2; wing of sheath c. 1 cm wide, inrolled ; blade very broadly cordate-sagittate, peltate, green, membranous, margin slightly undulate, almost erect, to 150 cm long, to 110 cm wide; anterior lobe c. 2/3 the length of the blade, the tip bluntly acute minutely apiculate; midrib with up to 6 primary veins diverging at an angle of 40°–70°, prominent abaxially and adaxially; sub marginal vein c. 0.5 cm from the margin; secondary veins flush with the lamina; interprimary collective veins inconspicuous; posterior lobes somewhat overlapping, to 56 cm long, peltate for 1/3 of their length; posterior costae diverging at c. 30°–50°. INFLORESCENCES several together; peduncle c. 55 cm long, greenish, elongated during fruit stage. Spathe c. 17 cm long, constricted at level of sterile zone of spadix; lower spathe 3–6 cm long, narrowly ovoid, green; limb erect, narrowly ovate, to 11 cm long, white, deciduous. Spadix almost the same length with the spathe; female zone c. 3.5 cm, with c. 150 pistils; interpistillar staminodes absent; ovary subglobose, greenish, c. 0.25 cm long, 0.2 cm in diam., with many ovules; stigma on very short style, almost sessile, cream, 4–6 lobed, rounded; sterile zone c. 3 cm long, white, attenuate, with c. 5 whorls elongated synandrodia; male zone white, c. 8 cm long, c. 2 cm wide; synandria irregularly rhombo-hexagonal, sometimes somewhat rhomboid, 1mm in diam.; thecae over-topped by synconnective, opening through lateral pores; appendix vestigial, constricted at base, c. 1 cm long, narrowly conical. Fruit a berry, oblong, c. 5 cm long, c. 3.5 cm wide; seed ovoid-cylindrical, numbering hundreds per infructescence, strongly ridged longitudinally, c. 0.1 cm long. Herbs, large to gigantic, evergreen, with massive, stout epigeal stem. Leaves very large; petiole pale green, strikingly pruinose, to 2.5m, proximal half sheathing; leaf blade white pruinose abaxially, especially when immature, green or pale green adaxially, ovate-cordate, 25–250 × 17–150cm, membranous, base cordate, peltate, margin undulate, apex shortly acuminate. Inflorescences 5–13 arising from leaf axil (actually terminal on shoot and displaced by new shoot); peduncle pruinose, cylindric, 30–80 × 1–2cm, each with a membranous cataphyll nearly equaling length of peduncle. Spathe 12–24cm; tube green, ellipsoid, 3–6 × 1.5–2cm; limb erect, white, oblong-boat-shaped, distinctly constricted, 8–19 × 2–3cm. Spadix 9–20cm; female zone white or cream-colored, conic; sterile zone 3–4.5cm, slender; male zone 5–14cm; appendix very short, 1–5mm, apex acute. Berry oblong, ca. 5 mm. Seeds many, fusiform, with many distinct longitudinal striations. 2n = 28.

Habitat

In the Malay Peninsula mainly, but not exclusively, on limestone; lithophytic to terrestrial, sometimes a pioneer after fire. In Java and Sumatera it is a common weed in disturbed places. Backer & Bakhuizen (1968:121) note its occurrence in mixed and teak forests, swamps, Imperata fields and in cultivation. Valley forests, limestone-associated, usually on moist but well drained sites, also cultivated.

Phenology

Fl. Apr–Jun, fr. Sep.

Vernacular

da ye yu