Histological analysis of the kinetics of AR formation in juvenile and mature cuttings of E. grandis . Cuttings were treated with IBA before placing in rooting tables. The bottom 1 cm of each cutting was fixed, embedded in paraffin and sectioned. A-E Juvenile cuttings. F-H Mature cuttings. Numbers refer to days after excision. Yellow arrows show meristematic cells. Phloem-p, Xylem-x, Cambium-c, Root promordia-rp.