algae

[ al-jee ]

plural noun

, singular al·ga [al, -g, uh].

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.

algae

/ 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

algae

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 .

Notes

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

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

Derived Forms

• algal, adjective

Other Words From

• al·gal [al, -g, uh, l], adjective

Word History and Origins

Origin of algae¹

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

Word History and Origins

Origin of algae¹

C16: from Latin, plural of alga seaweed, of uncertain origin

Example Sentences

A pungent, fishy rancid odor has been wafting through the coastal air in Los Angeles this week, an unfortunate consequence of beautiful bioluminescent algae that has graced local beaches for a fortnight.

From Los Angeles Times

Southern California beaches have recently experienced a “red tide” bloom of microscopic algae known as dinoflagellate, which give the ocean a rusty brown hue during the day and an electric blue glow when agitated by waves or other movement at night.

From Los Angeles Times

But now this bioluminescent algae is dying and releasing hydrogen sulfide gas, which causes a rotten egg smell, explained Laura Rink, associate director at Heal the Bay Aquarium in Santa Monica.

From Los Angeles Times

As bacteria feed on the decomposing algae, they consume oxygen, creating unbreathable patches of ocean known as dead zones, which can cause fish to die and worsen the smell, she said.

From Los Angeles Times

Neither the bioluminescent algae nor the odor it produces are harmful, said Rink.

From Los Angeles Times

Related Words

• seaweed