The top of a flower spike of a garden delphinium. The picture shows fasciation - a developmental abnormality. To bottom right, the stem of the spike, normally cylindrical, is flattened. It is curved and has ceased to elongate, instead producing a mass of flowers close together at its tip. The spike bears little resemblance to the tall tapering appearance of a normal delphinium in flower.Fasciation occurs sporadically in many plants, and has several possible causes, including bacterial infection. However, random occurrences in garden plants are most likely to result from trauma to the growing point (meristem) of the spike at an early stage of its development. This can happen due to mechanical damage, the actions of slugs, or exposure to frost or drought. Perennial plants will usually grow normally again in subsequent years |