From Wikipedia:
Acanthus (ornament) - "In architecture, an ornament is 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 spinosus 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. These sculptures were made from 75 BCE through 15 BCE."
Or
Acanthus (plant) - "Acanthus is a genus of about 30 species of flowering plants in the family Acanthaceae, native to tropical and warm temperate regions, with the highest species diversity in the Mediterranean Basin and Asia. Common names include Acanthus and Bear's breeches. The generic name is derived from the Greek word ακανθος (acanthos), meaning 'thorny.'"
File this under things I probably should have known something about with my background in architecture but I don't recall seeing this plant much before living in the Northwest. What a weird looking thing. It looks like it a stalk full of little hungry mouths eating bugs or something. And yet it's commonly carved into column capitals. The plants I've been seeing around Portland are also called "Spiny Bear's Breeches," a cute name.