Viburnum opulus

The American cranberrybush is from the northern parts of North America. It can be found from the Atlantic seaboard almost across to the Pacific, usually as one of the shrubs under the deciduous forest canopy, where it grows somewhat straggly due to lack of light. In sunnier spots it grows erect and dense.

The European cranberrybush, (V. opulus subsp. opulus) is closely related to the American, which Europeans often consider to be a subspecies (V. opulus subsp. trilobum) of the European species. In America, however, they are considered separate species, and several large-berried varieties have been developed there for fruit production.

American cranberrybush produces the abundant cream-coloured flowers typical of the viburnums, the outer ring of sterile flowers attracting insects. The fruits are yellowish berries which ripen in autumn to glowing red. The foliage also turns red in autumn. Given these characteristics and the edibility of the berries, the Americans themselves consider their native species superior to the European.

In 1753 when Linné gave this shrub the specific name opulus it was a reference to the field or hedge maple (Acer campestre), called by the Romans Opulus, which Guelder rose resembles in some ways, for example in the three-lobed leaves. Guelder rose grows naturally in Finland in rich mires and along streams.

Normally it reaches about 2m in height, with grey angular stems. The flower heads are made up of an outer ring of large showy white but sterile flowers, whose purpose is to attract pollinating insects to the fertile flowers in the centre. In autumn the leaves turn an attractive reddish. Formerly the species was considered poisonous but according to current opinion the red berries are not particularly poisonous, though they taste unpleasant. Occasionally the yellow-berried form (V. opulus f. xanthocarpum) can be found in gardens.

Guelder rose has beautiful flowers and fruit. Both flowers and fruit are most abundant in full sun, but then lots of moisture is necessary. In recent years the species has been troubled in places by the viburnum leaf beetle (Pyrrhalta viburni).