Vessel contents in the petiole of a transpiring sunflower leaf. Vessels containing water shown in green, gas spaces (embolisms) in red. Some vessels are completely embolized, others contain varying amounts of water as well as gas. The proportion of embolized vessels was followed during a day's transpiration. Petioles were snap-frozen intact on the transpiring plant, and viewed, still frozen, in the cryo-scanning microscope.
A silique of Arabidopsis thaliana enclosing ovules containing torpedo-shaped embryos cultured horizontally in a hormone-free, sucrose-containing medium, photographed 25 d after culture in the dark and 1 d in continuous light. Seedlingsarise by viviparous germination of embryos, which complete their development but do not lapse into dormancy. Normal plants are raised by subsequent transplantation of seedlings to soil vermiculite.