The plant shown above, Acanthus mollis L., is widely held by historians to be the inspiration behind a highly characteristic element of ancient Greek (Corinthian) and Roman architecture - the so-called 'Acanthus motif'. This feature is expressed mostly in column capitals, as shown below*.
For the Romans, the Acanthus plant held connotations of resurrection, as evidenced by the following quote from the architect Vitruvius:
The invention of the capital of this order is said to be founded on the following occurrence. A Corinthian virgin, of marriageable age, fell a victim to a violent disorder. After her interment, her nurse, collecting in a basket those articles to which she had shown a partiality when alive, carried them to her tomb, and placed a tile on the basket for the longer preservation of its contents. The basket was accidentally placed on the root of an acanthus plant, which, pressed by the weight, shot forth, towards spring, its stems and large foliage, and in the course of its growth reached the angles of the tile, and thus formed volutes at the extremities. - Marcus Vitruvius Pollio, 'De Architectura IV', 25 B. C.
Acanthus is a genus mostly native to the Mediterranean region, though it has been grown in many gardens around the world for its beautiful foliage and flowers. Its name in Maltese is Ħannewija.
*image by Jane Vadnal, University of Pittsburgh. Pictures of plant (1): Fiddien 27.V.2009; (2-3): Buskett 06.V.2009