1	Leaf apex rounded, retuse, or obtuse		(2)
+	Leaf apex acute, acuminate, or caudate		(4)
2 (1)	Sepals free, pubescent outside; petiole 0.7-1 mm wide; fruiting pedicel 0-1 mm; male disk consisting of free pubescent lobes; leaf base cordate to rounded, rarely obtuse; ovary pubescent.		1 A. ghaesembilla
+	Sepals fused for at least 2/3 of their length, glabrous or pubescent outside; petiole 1-2 mm wide; fruiting pedicel 1.5-3(-9) mm; male disk various but never consisting of free pubescent lobes; leaf base acute to rounded; ovary glabrous or pubescent		(3)
3 (2)	Leaves papery, dull, (2-)5-10(-21) cm; domatia present; disk pubescent, at least in male flowers; stamens (1 or)2(or 3); rudimentary ovary absent or small; fruit 4-6 × 3-4 mm; female inflorescence and infructescence 2-5(-9) cm.		2 A. acidum
+	Leaves leathery or thickly papery, shiny, (5-)10-18(-32) cm; domatia absent; disk glabrous; stamens 3 or 4(or 5); rudimentary ovary ca. 1 mm; fruit 5-11 × 4-7 mm; female inflorescence and infructescence (4-)10-18 cm.		3 A. bunius
4 (1)	Stipules 2-5(-7) mm wide, persistent; bracts subtending inflorescences and inflorescence branches conspicuous, resembling stipules; most of plant densely yellowish tomentose.		4 A. fordii
+	Stipules 0.2-2(-3) mm wide or caducous; bracts subtending inflorescences and inflorescence branches inconspicuous, not resembling stipules; indumentum various		(5)
5 (4)	Petiole 15-35 × 2-3 mm; sepals free, males 1-1.2 mm, females 1.5-1.8 mm; infructescence robust and usually unbranched, up to 17 cm.		5 A. nienkui
+	Petiole 0-15(-20) × 0.5-1.5 mm; sepals free or partially fused, either less than 1 mm (males) or ca. 1.5 mm (females), or fused for at least 2/3 of their length; infructescence unbranched or branched, mostly much shorter than 17 cm		(6)
6 (5)	Fruit with lateral styles inserted at ca. 1/4 of fruit length; stipules needlelike, ca. 0.2 mm wide, persistent; leaves usually bullate; disk and ovary hairy.		6 A. hainanense
+	Fruit and ovary with terminal styles (rarely subterminal in A. japonicum); stipules triangular-lanceolate, at least 0.5 mm wide or caducous; leaves not bullate; disk and ovary various		(7)
7 (6)	Sepals fused for more than 1/2 of their length		(8)
+	Sepals free to fused for up to 1/2 of their length		(10)
8 (7)	Fruit 5-11 × 4-7 mm, laterally compressed; male calyx 1-1.5 mm, flowers sessile; leaf blade (5-)10-23(-32) cm, without domatia, completely glabrous or abaxially pubescent; inflorescence axes robust, usually unbranched.		3 A. bunius
+	Fruit 3-6 × 2-4 mm, laterally compressed or terete; male calyx 0.3-0.5 mm, flowers sessile to pedicellate; leaf blade (2-)5-10(-21) cm, usually with domatia, pilose at least along major veins; inflorescence axes moderately thick to slender, usually branched		(9)
9 (8)	Leaf blade obovate to elliptic-oblong, drying yellowish green, whitish pubescent to glabrous, higher venation not conspicuously tessellated; calyx glabrous outside; male pedicel 1-1.5 mm; male disk cushion-shaped, enclosing filaments, pubescent; stamens (1 or)2(or 3); rudimentary ovary absent or minute; stigmas 3 or 4.		2 A. acidum
+	Leaf blade oblong to lanceolate, drying reddish brown, grayish, or olive green, yellowish pilose at least along veins abaxially, higher venation finely tessellated; calyx ± pubescent outside; male pedicel 0-1 mm; disk annular, sometimes divided into free alternistaminal lobes, glabrous; stamens 3 or 4; rudimentary ovary clavate to terete; stigmas 4-8.		7 A. sootepense
10 (7)	Ovary and fruit pubescent, laterally compressed; disk, at least in male flowers, pubescent; male disk consisting of free alternistaminal glands; stamens (4 or)5(-7); indumentum especially of young plant parts and inflorescences reddish to yellowish.		1 A. ghaesembilla
+	Ovary and fruit glabrous; disk glabrous; male disk cushion-shaped, fully or partially enclosing bases of filaments and pistillode; stamens 3-5; indumentum lacking or variously colored		(11)
11 (10)	Leaf blade ovate, apically long attenuate-acute; petiole (5-)8-15(-20) mm, not wider than 1 mm; female inflorescence and infructescence 2-5(-8) cm, axes reddish pubescent; Hainan.		8 A. maclurei
+	Leaf blade oblong or elliptic, apically acuminate; petiole 2-10(-20) mm, 0.5-2 mm wide; male inflorescence (1-)3-13 cm, female inflorescence 3-10 cm, infructescence 6-20 cm, axes whitish or yellowish pubescent; mainland China		(12)
12 (12)	Higher leaf venation finely tessellated, leaf blade often with domatia, yellowish pubescent at least along veins abaxially; calyx lobed for 1/4-1/2 of its length, margin never glandular-fimbriate, in female flowers pitcher-shaped; male disk annular, sometimes divided into free lobes alternating with stamens; fruit terete. ..... 7. A. sootepense		(12)
+	Higher leaf venation not conspicuously tessellated, leaf blade without domatia, usually glabrous except for whitish pubescence along major veins, or completely glabrous; calyx lobed for at least 1/2 of its length to sepals free, margin often glandular-fimbriate, cup-shaped; male disk cushion-shaped, fully or partially enclosing bases of filaments and pistillode or annular and 3-5-lobed, lobes extending inward between filaments to pistillode; fruit laterally compressed or terete		(13)
13 (12)	Fruit distinctly laterally compressed; inflorescence, pedicels, and flowers slender, usually very regular; petiole 0.5-1 mm wide; sepals often free; leaves papery to subleathery, often conspicuously flat and shiny, to 13 × 4.5 cm, elliptic or oblong-elliptic to oblong-lanceolate.		9 A. japonicum
+	Fruit terete; inflorescence, pedicels, and flowers of moderate to robust build; petiole 0.7-2 mm wide; sepals nearly free to halfway fused; leaves membranous to leathery, not conspicuously shiny or flat, to 25 × 10 cm, of variable shape.		10 A. montanum