Radial secondary growth and formation of successive cambia and their products in Ipomoea hederifolia L. (Convolvulaceae).

摘要: Ipomoea hederifolia stems increase in thickness using a combination of different types cambial variant, such as the discontinuous concentric rings cambia, development included phloem, reverse orientation segments, internal formation secondary xylem and phloem from cambium, differentiation cork pith. After primary growth, first ring cambium arises between external xylem, producing centrifugally centripetally. The stem becomes lobed, flat, undulating, or irregular shape result both continuous cambia. As is greater one region than another, this results grooved stem. Successive cambia formed after are two distinct functional types: (1) functionally normal successive that divide to form centripetally centrifugally, like other dicotyledons show rings, (2) abnormal with orientation. former type originates parenchyma cells located outside produced by previous cambium. latter develops conjunctive tissue at base This inverted, In later situated deep inside undergoes de-differentiation, re-differentiates into islands xylem. © 2008 Linnean Society London, Botanical Journal Society, 2008, 158, 30–40.