Shoot growth inDelonix regia takes place in three distinct flushes, the first commencing in mid-March, the second in late May and the third in October. The cambial reactivation starts in April after the initiation of the first flush of shoot growth, but the addition of new vascular derivatives does not take place until the second flush of shoot growth has occurred. Heavy flowering which ensues following first flush of shoot growth seems to delay cell divisions in cambial initials in April. Once the formation of cambial derivatives starts, it continues till mid-November whence the cambium enters the dormant phase. Xylogenesis begins from July and the formation of phloem in October, while the precursor phloem differentiates in early April.