palo fierro
/ˌpaləʊ fɪˈɛrəʊ/(also palo de fierro, palo fiero, palo de hierro) Chiefly US
noun
Any of various trees of desert regions in south-western North America with very hard, tough wood, especially desert ironwood, Olneya tesota (family Fabaceae (Leguminosae)).
Origin
Mid 19th century; earliest use found in Mayne Reid (1818–1883), novelist and children's writer. FromAmerican Spanish palo fierro, lit. ‘iron tree’, a name given to various trees or their wood from palo, specifically sense of palo + fierro (Spanish hierro) iron (from classical Latin ferrum: see ferro-).