Algae -Seaweed

Seaweeds are found from the intertidal zone to waters about 100 ft in depth and is characterized by its specific combinations of photosynthetic pigments. Thus, we have brown, red and green seaweeds. While they look like true plants, seaweeds differs by their lack of roots, flowers, seeds and true leaves. Instead they have holdfasts, stipes, blades and some larger kelps (brown seaweed) has pneumatocysts or gas-filled floats to lift the blades toward the sunlight. Holdfasts look like roots but instead of bringing minerals to the plant, it is merely an anchor to the ocean's floor. The stipe, which looks like a true plant's stem, is more of a shock absorber between the wave-tossed upper parts and the lower parts of the algae. There is however, like in plants, transportation of products of photosynthesis from the blades to algae's other parts. Photosynthesis also occurs in the stipe and holdfast. The blades differ from plant leaves in the fact that they have no veins and photosynthesis occurs on the top and bottom of the blade. Seaweeds reproduc both sexually and asexually.

Forming huge beds off the California coast, Giant Bladder kelp - Macrocystis pyrifera , a brown kelp, can reach 100 to 200 ft long. It is the fastest growing plant on earth, growing up to 10 inches a day, and can live up to 8 years given the right conditions, such as how calm of an area it grows in (although it needs a low level of constant water motion to survive). Darwin first published information about giant kelp on his voyages off South America. The giant kelp's habitat is mostly in the southern hemisphere off the coasts of Chile, Argentina, South Africa, southern islands of the Indian Ocean, southern Australia and New Zealand. The west coast of North America is the only northern hemisphere location.

Bull Kelp	Giant Kelp
	Pterygophora	Southern Sea Palm

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