One of the mysteries of the English language finally explained.
Any of several trees and shrubs yielding very hard heavy wood; specifically (a) Mesua ferrea (family Calophyllaceae), native to Sri Lanka and introduced in parts of South-East Asia; (b) Caesalpinia ferrea (family Caesalpiniaceae (Leguminosae)) of Brazil and other parts of South America.
Early 17th century. From iron + tree, so called on account of the hardness of the timber and also on account of its weight.
iron tree/ˈʌɪən ˌtriː/
In this article we explore how to impress employers with a spot-on CV.