Phytoplasma infection causes proliferation of axillary shoots. Healthy plant is on the right. Small, secondary, sterile florets issue from the original flower heads. Phytoplasma infection in E. purpurea . Note greening and distortion in disk and ray florets.
Normal flower appears on the right.
Diseased plants are subject to winter kill and infections caused by soil-borne pathogens. Since flower parts are changed into vegetative leaves and sterile florets in the infected plants, no seeds are produced. Therefore, the disease has a tremendous impact on echinacea seed production. Transmission electron and fluorescent microscopic techniques can be used to look for phytoplasma particles in the phloem tissues. Most of the phytoplasma bodies are spherical to ovoid or irregular in shape, surrounded by single membranes and lack cell walls.