Picea abies 'Tuberculata' / Tuberous Norway spruce

Picea abies 'Tuberculata' is the name assigned to a singular curiosity of a Norway spruce first found living in a garden in Kerkade, Limburg, The Netherlands. It is distinctive through tuberous growths covering the trunk and branches. These are thought to be a result of abnormal distribution of cortical cells at the bark surface. These growths are 1.5 to 3 inches (4 - 7 cm) high and stand out more than half of the body length. Other aspects of the plant are typical for the species. Similar plants, although rare have been described growing in forests in Scandinavia, suggesting that 'Tuberculata' is best used as a form name, i.e. Picea abies f. tuberculata. Specimens are virtually unknown in the nursery trade.

Swiss Botanist, Carl Joseph Schröter formally described the tree in botanical literature in 1898. It is a spontaneous natural mutation.

Picea abies 'Tuberculata' growing in a forest in Finland in 1996.
Photo by Miehikkälä