Leaves palmately divided to the base, usually more than 3-lobed.
la. Leaves 3-foliolate with the segments free to the base; plants terrestrial...........A. trisectum Sodiro
1b. Leaves 5-13-foliolate or lobed; plants epiphytic climbers.
2a. Huge scandent epiphyte; leaflets lobed; peduncle elongate; spadix to 75 cm long; spathe dark violet purple.......... A. clavigerum Poepp.
2b. Relatively small, scandent plants with long internodes; leaflets not lobed (except the basal leaflet); peduncle long or short; spadix less than 25 cm long; spathe green to purplish.
3a. Leaf segments all more or less equal, petiolules 4-6 cm long; peduncles slender and long, usually more than 20 cm long, longer than spadix; spadix whitish to greenish at anthesis..........A. kunthii Poepp.
3b. Leaf segments unequal, the lowermost more or less auriculate and usually markedly inequi-lateral; petiolules usually short, less than 2 cm long with the leaf tissue decurrent often almost to the base; peduncles short and stout, usually less than 6 cm long and shorter than the spadix; spadix lavender at anthesis..........A. pentaphyllum (Aubl.) G. Don var. bombacifolium (Schott) Madison.