Kelp Is Not A Plant

Although it resembles seaweed and relies on sunlight, kelp is not actually a plant. It belongs to a group of organisms called stramenopiles, making it more closely related to some types of algae than to flowers or trees.

This evolutionary twist highlights the complexity of life under the sea. While kelp performs photosynthesis just like a garden shrub, its cellular structure and genetics reveal a completely different lineage. Stramenopiles represent a massive group of organisms that includes everything from diatoms to the pathogen responsible for the Irish Potato Famine. By grouping kelp outside the plant kingdom, scientists gain a much clearer picture of how life diversified across the globe.