Roosid

Roosid is a nonstandard or historical variant spelling occasionally encountered in discussions of plant systematics. In contemporary botanical usage the preferred term is Rosids, the name of a major clade within the flowering plants. The form roosid is generally considered a misspelling or informal shorthand rather than the formal taxonomic name.

Rosids (also Rosidae in older classifications) constitute one of the largest diversifications of angiosperms, encompassing roughly 70,000 species in a wide range of families. They are defined primarily by molecular phylogenetic data rather than a single shared morphological trait, and they comprise two major lineages, the Fabids and the Malvids, which include many economically important groups.

Members of the Rosids display extensive ecological and morphological diversity. They include fruit crops such as apples, pears, and berries (Rosaceae), legumes and other crops (Fabaceae), mustards and crucifers (Brassicaceae), cotton and cacao (Malvaceae and related families), citrus fruits (Rutaceae), and many trees and shrubs in temperate and tropical regions.

Historically the Rosids were identified as a clade through molecular studies in the late 20th and early 21st centuries and are now a standard part of modern plant taxonomy. The term roosid remains a nonstandard variant and users are advised to employ Rosids in formal writing.