Japan Flora: Closely resembling A. sieboldii, but the leaves yellowish green, usually obtuse, 4-6 cm. wide; perianth-lobes fleshy, flat, obtuse, recurved above after anthesis. May-June.
Hokkaido. Sakhalin, s. Kuriles.
Russia Flora: Species closely related to the previous one, but with yellowish-green, rather obtuse, smaller leaves, fleshy obtuse perianth lobes, after flowering with margins curling to the middle. Stamens 6. Styles 3 in number. 2n=26 (Sokolovskaya, 1960, as "A. sieboldi").
North Sakhalin, South Sakhalin, South Kurils. (Fig. 6). — Mixed coniferous-broadleaved and broadleaved forests, up to middle mountain belt. Flowering VI—VII, fruiting VIII—IX. — General distribution: Japanese-Chinese. — Described from Sakhalin: "Hab. in Nadelwäldern im Moose, Duui, Ende Mai 1861 (fl.), Glehn, 22 VII 1860 (frf.), Glehn; Arkai, Anf. Juni 1860 (fl.), 8 VIII 1860 (fr. mat.) Glehn" (syntypes — LE).
Note. We share the opinion of V. N. Voroshilov (1982) about the restriction of A. heterotropoides to island territories. In the continental part of the Russian Far East only A. sieboldii grows.