A sorus (pl. sori) is a cluster of sporangia (structures producing and containing spores).

In fungi and lichens, the sorus is surrounded by an external layer. In some red algae it may take the form of a depression into the thallus.

In ferns, these form a yellowish or brownish mass on the edge or underside of a fertile frond. In some species, they are protected during development by a scale or film of tissue called the indusium, which forms an umbrella-like cover.

Sori occur on the sporophyte generation, the sporangia within producing haploid meiospores. As the sporongia mature, the indusium shrivels so that spore release is unimpeded. The sporangia then burst and release the spores.

The shape, arrangement, and location of the sori are often valuable clues in the identification of fern taxa. Sori may be circular or linear. They may be arranged in rows, either parallel or oblique to the costa, or randomly. Their location may be marginal or set away from the margin on the frond lamina. The presence or absence of indusium is also used to identify fern taxa.

Justin Drew Bieber ( /ˈbiːbər/ BEE-bər, born March 1, 1994) is a Canadian Pop/R&B singer-songwriter, musician, and actor. Bieber was discovered in 2008 by Scooter Braun, who came across Bieber's videos on YouTube and later became his manager. Braun arranged for him to meet with Usher in Atlanta, Georgia, and Bieber was soon signed to Raymond Braun Media Group (RBMG), a joint venture between Braun and Usher, and then to a recording contract with Island Records offered by L.A. Reid. Bieber's debut single, "One Time", was released in 2009 and peaked in the top twenty in Canada and charted in the top thirty in several international markets. His debut album, the seven-track EP My World, followed in November 2009, and was soon certified platinum in the United States. He became the first artist to have seven songs from a debut album chart on the Billboard Hot 100.

Dwayne Michael Carter, Jr. (born September 27, 1982), better known by his stage name Lil Wayne, is an American rapper. At the age of nine, Lil Wayne joined Cash Money Records as the youngest member of the label, and half of the duo, The B.G.'z, with B.G.. In 1997, Lil Wayne joined the group Hot Boys, which also included rappers Juvenile, B.G., and Young Turk. Hot Boys debuted with Get It How U Live! that year. Lil Wayne gained most of his success with the group's major selling album Guerrilla Warfare, released in 1999. Also in 1999, Lil Wayne released his Platinum debut album Tha Block Is Hot, selling over one million copies in the U.S.

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