Question: who introduced the poinsettia to the united states
[{'answer': 'Joel Roberts Poinsett', 'provenance': [{'wikipedia_id': '143540', 'title': 'Poinsettia', 'start_paragraph_id': 1, 'start_character': 357, 'end_paragraph_id': 1, 'end_character': 378, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '143540', 'title': 'Poinsettia', 'start_paragraph_id': 1, 'start_character': 4, 'end_paragraph_id': 1, 'end_character': 466, 'bleu_score': 0.8893846208718801, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1043474854278999236}, 'section': 'Section::::Abstract.'}]}]