Acanthus is a genus of about thirty species of flowering plants in the family Acanthaceae, native to tropical and warm temperate regions, with the highest species diversity found in the Mediterranean Basin and Asia. Common names for this plant include Acanthus and Bear's Breeches. The generic name derives from the Greek term for the Acanthus mollis, ἄκανθος, akanthos, a plant that was commonly imitated in Corinthian capitals.
Is it a symbol, or an ornamen? Well, it can be both:
The acanthus is one of the most common plant forms included in foliage ornament and decoration. It is probably the most significant element of the Corinthian Order, afavourite architectural style in Ancient Rome.
In architecture, an ornament may be carved into stone or wood to resemble leaves from the Mediterranean species of the Acanthus genus of plants, which have deeply-cut leaves with some similarity to those of the thistle and poppy. Both Acanthus mollis and the still more deeply-cut Acanthus spinous have been claimed as the main model, and particular examples of the motif may be closer in form to one or the other species. The leaves of both are in any case, rather variable in form. The motif is found in decoration in nearly every medium.
As a funerary symbol, the acanthus is often found on neo-classical graves, and may also be used to represent architects.