Oarweed facts for kids
Quick facts for kids Oarweed |
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| Scientific classification | |
| Genus: |
Laminaria
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| Species: |
digitata
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Laminaria digitata is a type of large, brown seaweed. It's also known as oarweed. You can find it in the cooler parts of the northern Atlantic Ocean, growing underwater near the coast.
Contents
What Does Oarweed Look Like?
Laminaria digitata is a tough, dark brown seaweed. It can grow to be very long, sometimes up to two or three meters (about 6 to 10 feet)!
It has a special part called a holdfast. This part looks like a cone with many root-like parts called rhizoids. The holdfast helps the seaweed stick tightly to rocks so it doesn't float away.
The stalk, or stipe, is strong and flexible. It can be over 2.5 centimeters (1 inch) thick and grow up to 1.5 meters (5 feet) long. The top part is called the blade. It looks like the palm of a hand with several finger-like sections.
You can tell Laminaria digitata apart from a similar seaweed, Laminaria hyperborea. Oarweed is usually darker and has a shorter stalk that doesn't break easily when you bend it.
How Oarweed Reproduces
Like many plants, oarweed has a special way of reproducing. Its life cycle involves two main stages. The large seaweed you see is one stage. It produces tiny spores. These spores grow into very small, microscopic plants. These tiny plants then produce new large seaweeds.
The spores are made in special patches called sori. These sori are found on the central part of the blade.
Where Oarweed Lives
Laminaria digitata lives in the northern parts of the Atlantic Ocean. In the west, it's found from Greenland all the way south to Cape Cod in the United States. In the east, it lives from northern Russia and Iceland down to France.
It's very common around the coasts of the British Isles. However, you won't find much of it along the east coast of England.
Oarweed's Environment
You'll mostly find Laminaria digitata in places where the ocean waves are strong. It grows on shores in the lower part of the littoral zone, which is the area covered by water at high tide and exposed at low tide. Here, it can form huge underwater "meadows" and is often the most common type of seaweed.
This seaweed grows quite fast. It can grow about 5.5% bigger each day! A square meter of ocean floor can hold about 40 kilograms (about 88 pounds) of this seaweed. It can reach lengths of about 4 meters (13 feet).
Sometimes, it grows near other seaweeds like Fucus serratus and Alaria esculenta. Sea urchins love to eat Laminaria digitata, so they can affect where it grows.
The amount of light, saltiness of the water, wave strength, temperature, and how much it dries out also affect where oarweed can live.
How People Use Oarweed
Laminaria digitata is harvested off the coasts of France and Morocco. It's used to make something called alginic acid. This acid is used in many products, including some cosmetics.
In the past, people used oarweed in different ways.
- It was traditionally used as a fertiliser to help crops grow better on land.
- In the 1700s, people burned it to get potash, which was used to make glass.
- In the 1800s, it was used to get iodine, a chemical element.
- Historically, the dried stalks of Laminaria digitata were used in traditional medicine for various purposes.
See also
In Spanish: Laminaria digitata para niños
