Acanthus is a genus of 22 mostly tropical species, native to North Africa, Asia and Australia, with three species native to southern Europe. The European species (Acanthus mollis and Acanthus spinosus) have been cultivated in Britain for centuries. These were familiar to the Bobarts, first keepers of the seventeenth-century Oxford Botanic Garden; Jacob Bobart the Younger grew and preserved a leaf and inflorescence of 'Spiny Bear's Breech'. The origin of the genus' common name Bear's Breech is not clear.
These two perennial plants make a statement in the garden having tall, erect spikes of white flowers with purple calyx-lobes and deeply dissected basal leaves. In the case of Acanthus spinosus, the leaves are extremely spiny, the spines being sharp and rigid, making them difficult plants to handle without discomfort! The species occurs naturally in Italy and Greece. The shiny, dark green, mostly hairless leaves of Acanthus mollis are softer without rigid spines. This species is native to the western and central Mediterranean.
The name Acanthus derives from the Greek word for spiny. A spiny bract subtends each flower which has a large upper calyx-lobe, in shades of green to purple, forming a hood over the corolla. The petals are fused with the lower lip usually having three lobes; four stamens are present. Bees are attracted to the flowers because of nectar production.
A few other species have been grown as ornamentals in the Oxford Botanic Garden including Acanthus dioscoridis, native to Turkey, Syria, Armenia and Iran, with pink petals. More recently an Ethiopian species has been cultivated, Acanthus sennii, shorter in stature than other species but with striking red flowers.
The attractive shape of Acanthus spinosus and Acanthus mollis leaves have long been chosen by architects and artists for ornamental designs. In the first century BCE, lobed Acanthus leaves were used as decorative ornaments of Corinthian columns. Motifs based on Acanthus leaf designs were also used in Roman times for decoration of grand buildings, followed by use in Byzantine art. Universally used in Italian Renaissance art, one example is found on the carved capitals of the Doge's Palace in Venice. Symbolism of the motif in Mediterranean countries is that of enduring life and immortality. In 1875 the English textile designer William Morris, used the leaf design for one of his renowned wallpapers. In the late 1960s, the founders of The Arts Society choose the Acanthus leaf as the Society's emblem.
Brummitt RK 1990. 157. Acanthus dioscoridis Acanthaceae. Kew Magazine 7: 161-165.
Christenhusz MJM et al. 2017. Plants of the world. An illustrated encyclopedia of vascular plants. Kew Publishing.
Cullen A et al. 2011. The European garden Flora, Volume V. Cambridge University Press.