1	"Leaves sith stipules"	"Viburnum opulus"
1	"Leaves without stipules"	2
2	"Plants evergreen shrubs; leaves entire"	3
2	"Plants deciduous shrubs; leaves renate or sharply toothed"	4
3	"Flowers more than 3 mm long; corolla lobes spreading; plants cultivated"	"Viburnum tinus"
3	"Flowers up to 3 mm long; corolla lobes erect"	"Viburnum cylindricum"
4	"Leaves with crenate margins; lower surfaces of leaves densely tomentose"	"Viburnum cotinifolium"
4	"Leaves with sharply toothed margins; lower surfaces of leaves not tomentose"	5
5	"Flowers opening after the appearance of leaves; corollas about 3 mm long"	"Viburnum mullaha"
5	"Flowers opening before the appearance of leaves; corollas 10-15 mm long"	"Viburnum grandiflorum"