Some seaweeds in this book are referred to by both their scientific and their common names. In a few cases a species will have more than one common name. To unravel this tangle of nomenclature, what follows is a seaweed list. This is not a compilation of the world’s seaweeds, which would fill tomes, but only a list of those referred to directly or by implication in the book.
The word algae is often used in the popular press. It can mean either microalgae, which are phytoplankton, or macroalgae, which are seaweeds. Microalgae are one-celled photosynthetic organisms, and those that live in the oceans drift on the water’s surface. Macroalgae, or seaweeds, are usually, but not always, anchored to rocks or some other firm surface. They are multicelled.
The word phycologist means simply an algae scientist.
Ulva lactuca: Sea lettuce. Like all green seaweeds, it requires the most sunlight and grows closest to shore. It is eaten by mollusks and crabs and sometimes by fish and people. Ulva’s distribution is worldwide.
Caulerpa taxifolia: The genus Caulerpa has a number of species within it. This particular one, taxifolia, originally from the Indian Ocean, has become a master invader of the Mediterranean.
Ascophyllum nodosum: This species of seaweed grows close to shore and provides habitat for many wild lives. It is harvested and made into hundreds of products in enormous quantities for industry. People call it rockweed, knotted wrack, and often—especially in the British Isles—kelp (although it’s not scientifically a kelp), or simply wrack.
The Fucus seaweeds: This genus contains a number of species that grow along the western North Atlantic, among them Fucus vesiculosus, or northern bladder wrack, Fucus spiralis, or spiral bladder wrack, and Fucus distichus, or flat bladder wrack. They are tough seaweeds and can withstand rough surf. In this book, the genus is referred to as Fucus or bladder wrack or rockweed. Both Ascophyllum and the Fucus seaweeds can be found growing along the rocky shore.
The Kelps: Kelps are members of the order Laminariales. They are strong and fast growing. Many species are edible and are harvested for food.
The kelps mentioned in this book that grow on the Pacific coast of North America are the bull kelp, Nereocystis luetkeana, and the giant kelp, Macrocystis pyrifera.
In the Atlantic, Alaria esculenta, or winged kelp, is harvested for food, as is Saccharina latissima, or sugar kelp, and sometimes Laminaria digitata, or horsetail kelp.
Undaria pinnatifida is a Japanese edible brown seaweed similar to the Atlantic seaweed Alaria. Its common name is wakame. Laminaria japonica is a seaweed in the kelp family used in many Japanese recipes. Its common name is kombu.
The Sargassum seaweeds: Hijiki is the Japanese name for Sargassum fusiforme, a popular edible seaweed in Japan.
Sargassum natans and Sargassum fluitans are the two free-floating seaweeds that make up the Sargasso Sea.
Chondrus crispus, like other red seaweeds, can grow in water up to two hundred feet deep or more, but it is also found in tide pools. The common names for it are Irish moss, on this coast, and carrageenan in Ireland.
Mastocarpus stellatus grows in the roughest surf, tightly attached to ledges and boulders. It withstands ice and harbors many small invertebrates on which birds feed.
Palmaria palmata grows in the intertidal zone. It thrives at the lowest ebb of the tide. It is called dulse along the western Atlantic, and dillisk in Ireland.
Porphyra umbilicalis: This species of seaweed grows along the western Atlantic coast down to Virginia. We call it laver. The genus Porphyra grows worldwide. In Japan a number of species of Porphyra are raised in large aquaculture projects and are sold as nori.