compactum

Compactum is a Latin term used in biological nomenclature as a descriptive epithet. It denotes a compact, dense, or tightly arranged form and is commonly found as the neuter singular form of the adjective compactus. In scientific naming, the form of the epithet must agree with the gender of the genus name, so compactum may appear with neuter genera, while compactus or compacta may occur with masculine or feminine genera.

In practice, compactum appears across plants, animals, and fungi to indicate a compact growth habit, dense clustering of leaves or flowers, or other compact structural features observed by the describer. The epithet is descriptive rather than taxonomically informative about relationships; it does not imply any systematic connection among different species that share the epithet.

Among taxonomic codes, the use of compactum is subject to standard nomenclatural rules for Latin epithets, including latinization, orthography, and publication requirements. As with other descriptive epithets, it is reused in many genera and across continents, leading to numerous species bearing the same epithet in disparate lineages.