Chock-full of chromosomes

By Amy Weiss

May 8 2019

Behold this fern which has the highest recorded chromosome number of any living organism.

Humans have 23 pairs of chromosomes, while this species of adder's-tongue fern, Ophioglossum reticulatum, has 630 pairs of chromosomes—some populations have been reported to have 720 pairs.¹ That's a total of 1,440 chromosomes per cell, and holds the Guinness world record!²

More about: Ferns


¹ Khandelwal, S. 1990. Chromosome evolution in the genus Ophioglossum L. Botanical Journal of the Linnean Society 102: 205-217.

² Guinness World Records. 2019. Most chromosomes. Available at: (Accessed 26 Apr 2019).