Fig. 1.

Representative images of the investigated species prior to and during the freezing treatment (horizontal black bar = 1.0 cm). (A1) Digital image of twigs of E. hermaphroditum with attached reproductive buds, (B1) C. vulgaris bearing flowers and (C1) L. procumbens with attached fruits. Ice nucleation, initiated in the vegetative stems, occurred at −4.7 °C, −2.8 °C and −1.0 °C in E. hermaphroditum, C. vulgaris and L. procumbens, respectively. Freezing events are visualized as brightened regions in the image, while unfrozen areas appear black. The IDTA image sequences show unblocked ice propagation in the vegetative shoot of each species (2–5). After a time lapse and at significantly lower temperatures single buds, flowers, or fruits froze independently from the vegetative shoot and from each other (6–10). Actual temperatures are indicated in the top right corner of each image. The time span (in hours, minutes and seconds) after initial ice nucleation in the vegetative shoot is indicated at the bottom right corner of each image.