Representative images of L. procumbens and C. vulgaris prior to and during the freezing treatment (horizontal black bar = 1.0 cm). (A1) Digital image of twigs of L. procumbens with attached fruits, and (B1) C. vulgaris shoots bearing flowers. Initial ice nucleation in the vegetative stem occurred at −3.1 °C and −5.8 °C in L. procumbens and C. vulgaris, respectively. Freezing events are visualized as brightened regions in the image, while unfrozen areas appear black. IDTA image sequences show ice nucleation in the vegetative shoot and subsequent unhindered ice propagation throughout the whole vegetative shoot in each species (A2-5, B2-4). Ice nucleation was initiated in the region of the calyx (white arrows) of reproductive shoots (A6: L. procumbens fruit; B5: C. vulgaris flower). IDTA images indicate that the ice barrier is localized at the base of the pedicel (A7, A10, B6 and B10). Red circles in the digital images (A1 and B1) indicate the location of the structural ice barrier. Temperatures are indicated in the top right corner of each image. The time span (in hours, minutes and seconds) after ice nucleation in the vegetative shoot is indicated in the bottom right corner of each image.