Compactus
/kom-PAK-tus/🏷️ Taxonomy● Basic
Also known as: compacta, compactum
A form epithet describing a plant with a dense, tightly packed, close-growing habit — whether in its overall form, flower clusters, or foliage arrangement. It is often applied to selected cultivars bred for a neater, denser form than the species. Appears as compactus (masculine), compacta (feminine), or compactum (neuter).
Etymology
From Latin compactus, past participle of compingere, meaning "to fasten together," from com- (together) + pangere (to fasten).
Example
“Berberis thunbergii 'Compacta', Spiraea japonica 'Compacta', and countless other dwarf shrub selections carry this epithet to signal their dense, tidy, space-efficient habit compared to the standard form.”