algae

Noun

 * 1) Algal organisms viewed collectively or as a mass; algal growth.
 * 2)  A particular kind of alga.
 * 1)  A particular kind of alga.
 * 1)  A particular kind of alga.

Usage notes

 * Etymologically, algae is the plural of, but algae is sometimes used as an uncountable noun with singular verb agreement (similar to the usage of the word ), or as a count noun to refer to a type of algae. The plural form may be considered nonstandard.