algae

American  

[al-jee] / ˈæl dʒi /

plural noun

singular

alga

1. Microbiology. any of numerous groups of chlorophyll-containing, mainly aquatic, eukaryotic organisms ranging from microscopic single-celled forms to multicellular forms 100 feet (30 meters) or more long, distinguished from plants by the absence of true roots, stems, and leaves and by a lack of nonreproductive cells in the reproductive structures: classified into the six phyla Euglenophyta, Crysophyta, Pyrrophyta, Chlorophyta, Phaeophyta, and Rhodophyta.

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algae British  

/ ˈældʒiː, ˈælɡəl /

plural noun

1. unicellular or multicellular organisms formerly classified as plants, occurring in fresh or salt water or moist ground, that have chlorophyll and other pigments but lack true stems, roots, and leaves. Algae, which are now regarded as protoctists, include the seaweeds, diatoms, and spirogyra

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algae Cultural  

1. Primitive organisms that contain chlorophyll but do not have structures, such as xylem and phloem, to transport fluids. Algae sometimes contain only a single cell, and nowadays they are not considered members of the plant kingdom.

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Discover More

Algae supply a considerable part of the world's oxygen.

The most familiar algae are the greenish scum that collects in still water.

Other Word Forms

• algal adjective

Etymology

Origin of algae

First recorded in 1790–1800; from New Latin, plural of Latin alga “seaweed”

Compare meaning

How does algae compare to similar and commonly confused words? Explore the most common comparisons:

• algae vs. seaweed

Example Sentences

But, with retreating sea ice, there is less under-ice algae to feed the amphipods that in turn feed the whales.

From Los Angeles Times

Barry explains how the slime mould feed off bacteria, algae and types of fungi and are an important part of the ecosystem.

From BBC

Last year, scientists in the country announced they had launched successful trials spraying the soil with cyanobacteria, also known as "blue-green algae" -- a method that helps retain moisture and facilitate tree rooting.

From Barron's

As they feed on seaweed and seagrass, they trim back algae and help protect slow-growing species such as corals and certain calcifying algae.

From Science Daily

More complex eukaryotic cells eventually evolved, giving rise to algae, fungi, plants and animals.

From Science Daily

Related Words

• seaweed