You are here
Araceae
Xanthosoma acutum E.G.Gonç.
SUMMARY
Geophytic herbs. Stem tuberous, 2.5-3 x 3.6-4 cm, producing long stolon-like offsets. Leaves 2-4; petioles 36-40 x 0.5-0.6 cm, smooth, apical portion flattened adaxially; sheath chartaceous, up to 15 cm long; leaves 2-4, leaf blade hastate-sagittate, 20- 24 X 21-22 cm, dark glossy green adaxially, paler and glossy adaxially, usually with white spots, repand margins; anterior division ovate 14-15 x 13-14 cm, apex acuminate, acumen up to 1.3 cm long, primary lateral veins 2-3 per side, departing midrib at 45-55° angle, sunken adaxially, prominent abaxially, concolorous in both sides, collective vein irregular, 1-11 mm from leaf margin; posterior divisions 9-11 x 10- 11.5 cm, ovate, posterior lobes with acuminate apex, acroscopic veins 1-2, basioscopic veins 2-4, basal vein naked for 0.9-1.1 cm. Inflorescences solitary or in pairs; peduncle erect, almost as long as the petioles, 17-27 X 0.4-0.6 cm, green tinged with red; spathe 8.3-9 cm long, strongly constricted at anthesis; spathe tube medium green outside, whitish green inside, 3.7-4 cm long, 2-2.2 cm in diameter; spathe lamina yellowish before anthesis, turning white on both sides at anthesis, ovate to elliptic, 4.5-5 x 2.3-2.6 cm, acuminate, acumen 0.6-l.3 cm long; spadix sessile, obliquely attached basally, up to 6-6.6 cm long, strongly constricted at the middle; female portion cylindrical, 1.6-1.7 x 0.8-0.9 cm, adnate to the spathe up to 7 mm; sterile male portion strongly constricted, strongly dimorphic, 1.9-2 cm long, 0.7-1 cm diam. at base, pure white; male portion cylindrical, 3-3.6 x 0.5-0.6 cm, ivory white. Flowers: synandria prismatic, irregularly hexagonal in upper view, 2-2.5 x 2-2.5 mm, pollen extruded in strands; lower staminodes prismatic, 3-4 x 4-5 mm, upper staminodes ca. 1 cm long, up to 5 mm long and 1-1.5 mm wide in upper view; gynoecium 1.5-2 mm long, style whitish, ca. 1.5 mm diam., stigma pale green, hemispherical, ca. 1 mm diam., ovary ovoid to barrel-shaped, 1.5 x 1.5 mm, locules 3-4, ovules 6-8 per locule, anatropous. Berries unknown.