How does a plant cross a body of water to colonize an island? If the fruit, containing the seeds, is able to float then it is a matter of falling into the water and catching the right currents. This is most likely the way seakale arrived on Texel in the previous century. The plant grows in salty environments on rocky or sandy bottoms. The round, nut-like seed pods contain 1 seed each and can survive a long journey at sea. Darwin discovered seakale seeds that had floated 37 days in seawater and still germinated! You know when seakale flowers from its strong fragrance.