Possible Clues:

• Muttering on stage about edible stalks, repeatedly
• Word repeated by actors to simulate conversation
• Edible plant; nonsense
• Its leaves are poisonous. Nonsense!
• Deplore outspoken insult that's mumbled on stage
• Fruitful theatrical conversation piece?
• Plant with fleshy reddish leaf-stalks used like fruit
• Reddish, fleshy-stalked plant, makes nice tart
• Reddish stalks - word repeated to simulate conversation
• Garden plant with reddish leaf-stalks