Webster’s Revised Unabridged Dictionary · 1913
Laburnum
La·bur′num (·nŭm), n. [L.] (Bot.) A small leguminous tree (Cytisus Laburnum), native of the Alps. The plant is reputed to be poisonous, esp. the bark and seeds. It has handsome racemes of yellow blossoms.
☞ Scotch laburnum (Cytisus alpinus) is similar, but has smooth leaves; purple laburnum is C. purpureus.