Picea glauca showing witches' brooms in late summer, when covered with spermogonia and mature aecia.
Witches' broom of spruce, taken in early summer, when the aecia are still immature.
Young C. arctostaphyli broom on spruce.
Mature C. arctostaphyli broom on spruce.
Living current-year needles covered with aecia (centre) and dead previous year needles still attached.