1	Calyx absent		(2)
+	Calyx present		(5)
2 (1)	Female flower with staminodes around ovary		(3)
+	Female flower without staminodes		(4)
3 (2)	Staminodes 10; leaf blade not papillate below, lateral veins slender and dense, visible on both surfaces.		1 D. macropodum
+	Staminodes 5; leaf blade finely (or minutely) papillate below, lateral veins laxly arcuate, slightly impressed adaxially, prominent abaxially.		2 D. himalense
4 (2)	Leaf blade narrowly lanceolate, 11.5-15 × 2.5-3 cm; infructescence ca. 2.5 cm; fruit smooth, style branches deciduous.		3 D. angustifolium
+	Leaf blade large, oblong-elliptic, 16-26 × 6-9 cm; infructescence 10-16 cm; fruit tuberculate, style branches persistent.		4 D. longeracemosum
5 (1)	Calyx 0.5-1 mm, deciduous		(6)
+	Calyx persistent		(7)
6 (5)	Leaf blade lanceolate, obovate-lanceolate, oblong, or oblong-lanceolate, 9-14 × 2.5-4 cm, glaucous and finely papillate below.		5 D. oldhamii
+	Leaf blade oblong-elliptic or oblong, 10-15(-21) × 3-6(-7) cm, not glaucous and not papillate below.		6 D. chartaceum
7 (5)	Calyx 2-3 mm; leaf blade green in dried state, glaucous below		(8)
+	Calyx less than 1.5 mm; leaf blade dark brown in dried state, not glaucous below		(9)
8 (7)	Leaf blade obovate or obovate-elliptic, 9-16 × 4-9 cm, apex obtuse or rounded; fruit ca. 7 mm, glaucous, densely arranged.		7 D. calycinum
+	Leaf blade oblong-elliptic, (16-)20-37 × 7-14 cm, apex acuminate; fruit 10-15 mm, not glaucous, laxly arranged.		8 D. majus
9 (7)	Leaf blade thinly coriaceous, 9-17 × 3-6 cm, apex falcate-acuminate or shortly acuminate, base broadly cuneate or cuneate, lateral and reticulate veins prominent on both surfaces, petiole 1.5-3.5 cm.		9 D. paxianum
+	Leaf blade thickly coriaceous, 6-9 × 2-2.5 cm, apex acute, base rounded or truncate, lateral veins visible on both surfaces, reticulate veins obscure, petiole 5-7 mm.		10 D. subverticillatum