In a new study published in the journal iScience, researchers from the Royal Botanic Gardens, Kew and the Institut Botànic de Barcelona (IBB-CSIC) in Spain present a new record-holder for the largest amount of DNA stored in the nucleus of any living organism on the planet.
The article doesn’t mention the size, but the stem is 15~30cm long, and most of its height. For comparison some ferns reach 100x that size.