Xanthosoma pentaphyllum
Seasonally dormant geophytes. Stem tuberous, 1.5-2 X 1.5-3 cm, with abundant ovoid cormels. Petioles 30-48 x 0.6-1 cm, glabrous, sheath 10-12 cm long, equaling up to 1/3 of the petiole length. Leaf blade 2-3, pedatilobed, 20-21 x 20-25 cm, lobes 3-7, central lobe 12-23 x 11-17 cm, 1.2-1.8 times longer than wide, ovate to wide-elliptic, base cuneate to obtuse, apex acuminate, secondary nerves 5-8 per side, arising at an angle of 30-50°, converging in a collective vein imprecisely outlined, lateral lobes equaling 70-80% the length of the central lobe, 10-18 x 3.5-11 cm, ovate, oblique. Inflorescence solitary. Peduncles 10-19 X 0.2-0.4 cm. Spathe green outside, white with a purplish base inside, 11-12 cm long, tube 2.5-4 x 1.5-3 cm, blade 8.5-9 x 4-5 cm. Spadix 6-10 cm long, fertile male portion 3.5-5.5 x 0.5-0.9 cm, sterile male portion 2.2-3.5 x 0.3-0.8 cm, female portion 1.3-1.5 x 0.5-0.7 cm. Synandria 3-6-androus, prismatic, 2 x 4 mm, staminodes irregularly flattened, gynoecium prismatic, ca. 2 x 2 mm, discoid style, stigma pale yellow. Spathe tube persisting in fruiting spadix. Berries 3-4 x 2-3 mm, white to greenish. Seeds ovoid, ca. 1.5 x 1 mm. Figure 17.
Xanthosoma pentaphyllum occurs from southern Ceara State (Northeastern Brazil) to Parana State (Southern Brazil), but seems to be more abundant in limestone outcrops. In limestone areas, it usually occurs in dense populations, sometimes completely crowded in fissures or pockets in the bare rock. This geophytic species, like the other two commonly found in limestone outcrops in Central-western Brazil, stays leafless during the dry season.