Acanthus, Bear's breeches (Acanthus mollis)
The deeply divided, spiny leaves and tall white flower spikes of this Mediterranean native make an architectural statement in the garden. In fact, acanthus is the plant you see carved on the Corinthian capitals of Greek and Roman buildings. Touchy about temperature—may flop in the hottest part of the summer and freeze below 15 degrees—so if you must have a perfect plant all year, this one’s not for you. Comes back strongly in the temperate seasons though, and stunning enough to make it worth the trouble. (inset: flower spike)