This large frond of Bull Kelp (Nereocystis luetkeana) had washed up on the beach. The round, hollow end of the frond keeps the end of the kelp frond near the surface. I was surprised to learn that 10% of the gas in the float is comprised of carbon monoxide! The root-like holdfasts anchor the fronds to the rocks. Kelp (and other seaweeds) is not a plant, it is a type of brown algae in the Kingdom Protista. Some types of kelp contain chemicals such as carrageenan and algin, many people would be amazed to know that a lot of the foods they eat and their toothpaste contain these chemicals!
Kudzu, the "vine that ate the South", has nothing on this kelp, it can grow up to 10 inches a day! It grows up to 115 feet long. According to the Monterey Bay Aquarium's website, the genus name, Nereocystis means "mermaid's bladder"! Who says taxonomists (people who name organisms) don't have a sense of humor! :)