radicel
/ˈradɪsɛl/Chiefly Botany. Now rare
noun
A fine or fibrous root; a secondary or adventitious root, a rootlet.
Origin
Early 19th century; earliest use found in John Lindley (1799–1865), botanist and horticulturist. From French radicelle rootlet from classical Latin rādīc-, rādīx + French -elle.