Arboreus
/ar-BOR-ee-us/🏷️ Taxonomy● Basic
Also known as: arborea, arboreum
Arboreus marks a species that grows as a tree, or at least takes a tree's form — woody framework, a raised crown — where its closest relatives are shrubs or soft-stemmed herbs. On a plant label it is a practical warning, because it means the plant will eventually want the room a small tree needs rather than the space you allowed for a border perennial. Compare arborescens, "becoming tree-like", which suggests a plant heading towards that form rather than one that reliably arrives at it.
Etymology
From Latin arboreus, "resembling a tree, of trees", from arbor, a tree.
Example
“Lupinus arboreus, the coastal bush lupine, earns its epithet: it builds a woody framework where most lupins stay soft-stemmed.”