island tree poppy References island tree poppy plant Ask Anything Homework Help Also known as: Dendromecon harfordii Written by The Information Architects of Encyclopaedia Britannica The Information Architects maintain a master list of the topics included in the corpus of Encyclopædia Britannica, and create and manage the relationships between them. The Information Architects of Encyclopaedia Britannica Britannica AI Ask Anything Learn about this topic in these articles: tree poppyThe related island tree poppy (Dendromecon harfordii), endemic to the Channel Islands off the southern California coast, reaches a height of 6 metres (20 feet). Tree poppies are hardy as ornamentals only in areas with mild winters. Read MoreThe related island tree poppy (Dendromecon harfordii), endemic to the Channel Islands off the southern California coast, reaches a height of 6 metres (20 feet). Tree poppies are hardy as ornamentals only in areas with mild winters. Read More