algae

[al-jee]

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.

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.

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

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

But there is not yet any scientific connection between the algae and any problems with eels or fish.

From BBC

The greater flamingo's pink colouring comes from a diet high in carotenoids - pigments found in algae and invertebrates such as shrimp.

From BBC

“Are you worried about the algae at all?”

From Salon

The algae bloom led to widespread domoic acid poisoning, with sea lions having seizures or falling into a comatose state.

From Los Angeles Times

Halligan said this type of bacterial or algae poison — which might be surging in the canal due to heat — can cause vomiting, drooling, weakness, seizure and, eventually, death.

From Los Angeles Times

Related Words

• seaweed