in an unprecedented experiment Russian scientists reserruct Silene Stenophylla seeds 30,000-year-old

Seeds of ancient plants aged between 40,000 and 25,000 years have been previously discovered in the region, mainly in rodent nests, but scientists were unable to resurrect them.

The seeds were firmly cemented together and often totally filled with ice in a kind of natural freezing chamber, which made any water infiltration impossible and helped preserve the seeds.

Sources:
en.rian.ru
ABC.net
WashingtonPost