Specialized parenchyma cells in flowering plant phloem that are closely associated with sieve tube elements. They retain their nuclei and organelles to support the metabolic functions of the enucleate sieve tubes.
From Old French 'compaignon' meaning 'one who shares bread' and Latin 'cella' meaning 'small room.' The term emerged in the late 19th century, reflecting how these cells literally 'accompany' and support sieve tubes like faithful companions.
Companion cells are the ultimate plant wingmen! Since sieve tubes gave up their nuclei to become better transport tubes, companion cells stepped up to be their brains, controlling everything from protein synthesis to metabolic regulation - true cellular teamwork.
Complete word intelligence in one call. Free tier — 50 lookups/day.