The ornamental japonica yields a fruit which is a type of quince and has a similar flavour. Wash the fruit, but do not peel or core. Slice the fruit and simmer in the water until tender. Put through a sieve and weigh the pulp. Add an equal weight of sugar and the cloves. Stir over low heat until the sugar has dissolved. Boil hard to setting point, pour into hot jars and cover.