Russian scientists grew the plants above from the innards of fruit that had been frozen for 30,000 years. From Discover:
The plant owes its miraculous resurrection to a team of scientists led by David Gilichinsky, and an enterprising ground squirrel. Back in the Upper Pleistocene, the squirrel buried the plant’s fruit in the banks of the Kolyma River. They froze.
Over millennia, the squirrel’s burrow fossilized and was buried under increasing layers of ice. The plants within were kept at a nippy -7 degrees Celsius, surrounded by permanently frozen soil and the petrifying bones of mammoths and woolly rhinos. They never thawed. They weren’t disturbed. By the time they were found and defrosted by scientists, they had been buried to a depth of 38 metros, and frozen for around 31,800 years…
Svetlana Yashina from the Russian Academy of Sciences grew the plants from immature fruits recovered from the burrow. She extracted their placentas – the structure that the seeds attach to – and bathed them in a brew of sugars, vitamins and growth factors. From these tissues, roots and shoots emerged.
“Flowers regenerated from 30,000-year-old frozen fruits, buried by ancient squirrels“