A clump of Primula florindae, growing in a garden in Norfolk UK, photographed in mid August, as seed heads were developing. The picture demonstrates phyllody - the process whereby the normal development of flowers is disrupted, giving rise to leaves. This can produce completely "green" flowers; for example, by roses when each petal develops as a leaf.In this picture, some of the flower primordia in the centre of the inflorescence of the plant have developed into single leaves.The cause of a particular occurrence of phyllody is difficult to determine. It may be due to environmental (climatic) factors. Many cases arise from infection with mycoplasmas, which are very small pleiomorphic bacteria. In plants they are known as phytoplasmas. Both climatic factors and infections can cause disturbance to plant hormone levels, resulting in developmental abnormality.