Question: where do secondary xylem and phloem cells arise from
[{'answer': 'The vascular cambium', 'provenance': [{'wikipedia_id': '227675', 'title': 'Vascular cambium', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 20, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'the vascular cambium', 'provenance': [{'wikipedia_id': '227675', 'title': 'Vascular cambium', 'start_paragraph_id': 1, 'start_character': 708, 'end_paragraph_id': 1, 'end_character': 728, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '227675', 'title': 'Vascular cambium', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 496, 'bleu_score': 0.6735727319364011, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1226388446188216140}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '3094833', 'title': 'Vascular tissue', 'section': 'Section::::Abstract.', 'start_paragraph_id': 3, 'end_paragraph_id': 3, 'meta': {'evidence_span': ['In stems and roots, the xylem typically lies closer to the interior of the stem with phloem towards the exterior of the stem. In the stems of some Asterales dicots, there may be phloem located inwardly from the xylem as well. Between the xylem and phloem is a meristem called the vascular cambium.', 'Between the xylem and phloem is a meristem called the vascular cambium.', 'In stems and roots, the xylem typically lies closer to the interior of the stem with phloem towards the exterior of the stem. In the stems of some Asterales dicots, there may be phloem located inwardly from the xylem as well. Between the xylem and phloem is a meristem called the vascular cambium.']}}]}, {'provenance': [{'wikipedia_id': '56333', 'title': 'Root', 'section': 'Section::::Growth.\n', 'start_paragraph_id': 36, 'end_paragraph_id': 36, 'meta': {'evidence_span': ['The former forms secondary xylem and secondary phloem, while the latter forms the periderm. In plants with secondary growth, the vascular cambium, originating between the xylem and the phloem, forms a cylinder of tissue along the stem and root. The vascular cambium forms new cells on both the inside and outside of the cambium cylinder, with those on the inside forming secondary xylem cells, and those on the outside forming secondary phloem cells. As secondary xylem accumulates, the "girth" (lateral dimensions) of the stem and root increases.', 'The vascular cambium forms new cells on both the inside and outside of the cambium cylinder, with those on the inside forming secondary xylem cells, and those on the outside forming secondary phloem cells.']}}]}]