1	Lateral veins of leaflets numerous, parallel.		26 A. costatum
+	Lateral veins not parallel		(2)
2 (1)	Central leaflet obovate, obcordate, or obdeltate, shorter than wide		(3)
+	Central leaflet elliptic, ovate, or rhombic, longer than wide and as long as lateral lobes		(9)
3 (2)	Spadix appendix not or slightly exserted from spathe		(4)
+	Spadix appendix distinctly exserted from spathe		(6)
4 (3)	Spadix appendix filiform.		32 A. bonatianum
+	Spadix appendix subcylindric, apex rounded		(5)
5 (4)	Pseudostem, petiole, and peduncle verrucose or finely asperate.		33 A. asperatum
+	Pseudostem, petiole, and peduncle smooth.		34 A. brucei
6 (3)	Inflorescence ca. as high as leaf blade.		35 A. wilsonii
+	Inflorescence distinctly below leaf blade		(7)
7 (6)	Spadix appendix basally densely rugose.		31 A. handelii
+	Spadix appendix smooth throughout		(8)
8 (7)	Spathe smaller, tube 1.5-3.5 cm.		37 A. parvum
+	Spathe larger, tube 3-5 cm.		36 A. elephas
9 (2)	Underground stems rhizomatous or spathe throat galeate-auriculate; all leaflets petiolulate		(10)
+	Underground stems tuberous; spathe throat not galeate-auriculate; leaflets basically sessile		(12)
10 (9)	Spathe limb not winged sideways; stems thickly rhizomatous.		30 A. speciosum
+	Spathe limb winged sideways and galeate-auriculate		(11)
11 (10)	Underground stems rhizomatous, cylindric.		23 A. dahaiense
+	Underground stems tuberous, subglobose.		22 A. lingyunense
12 (9)	Spathe tube lamellate inside		(13)
+	Spathe tube not lamellate inside		(14)
13 (12)	Spathe limb not winged sideways.		27 A. utile
+	Spathe limb winged sideways and vexillate.		28 A. vexillatum
14 (12)	Spathe limb ovate-lanceolate, apex long acuminate to caudate.		25 A. intermedium
+	Spathe limb obovate, apex cucullate or 3-lobed		(15)
15 (14)	Leaflets covered with golden scales abaxially; spathe limb cucullate.		24 A. pianmaense
+	Leaflets without trichomes; spathe limb distinctly 3-lobed.		29 A. tengtsungense