1	Fruit completely separate from or slightly adnate to persistent calyx; ovary superior.		(2)
+	Fruit partially or almost completely adnate to persistent calyx; ovary inferior.		(4)
2 (1)	Ovary 3-locular when young, becoming 1-locular; seeds 1 or 2, without wings, rounded at both ends; pedicel not jointed		1 Styrax
+	Ovary 5(or 6)-locular; seeds numerous, winged or acute at both ends; pedicel jointed.		(3)
3 (2)	Filaments coherent or slightly connate at base; fruit drupaceous, indehiscent, pear-shaped; seeds pointed at both ends		2 Bruinsmia
+	Filaments connate at least to middle; fruit capsular dehiscing loculicidally by 5 valves; seeds winged at both ends		3 Alniphyllum
4 (1)	Fruit dehiscing loculicidally by 3 valves; seeds winged at both ends; petals free, connective 2- or 3-dentate		4 Huodendron
+	Fruit indehiscent; seeds without wings; petals connate at base (shortly coherent in Pterostyrax), connective entire.		(5)
5 (4)	Corolla lobes 4(or 5); fruit with 2--4 wings		5 Halesia
+	Corolla lobes 5 (4--7 in Sinojackia); fruit with 5--12 ribs or wings (Parastyrax without ribs or wings).		(6)
6 (5)	Flowers solitary or 2 together; filaments of equal length		6 Melliodendron
+	Flowers in racemes, panicles, or thyrses; filaments 5 long and 5 short or subequal (sometimes equal in Sinojackia).		(7)
7 (6)	Leaf blade margin entire or callose-denticulate; inflorescences crowded		10 Parastyrax
+	Leaf blade margin serrate or serrulate; inflorescences not crowded.		(8)
8 (7)	Winter buds enclosed by scales; fruit apex with a short point		9 Rehderodendron
+	Winter buds naked; fruit apex tapering into a beak.		(9)
9 (8)	Inflorescences paniculate; calyx tube campanulate; fruit exocarp thin, crusty		7 Pterostyrax
+	Inflorescences racemose cymes; calyx tube obconical; fruit exocarp thick, woody or fleshy		8 Sinojackia