A vocabulary of landscape — a landscape of words
1336 entries
ferruginous
Ferruginous means rust-colored, a reddish brown with iron in it, and by extension it describes anything containing or stained by iron. It is a working word in ornithology, botany, and geology, where it names both a color and a chemistry. Ferruginous rock is rock with enough iron to color it; a ferruginous spring runs orange over the stones below it.
Etymology
The word comes from the Latin for iron rust, built on the Latin word for iron, which is also the source of ferrous and ferric and the chemical symbol Fe. It belongs to the same shelf of specialist color words as cinereous for ash gray and fuscous for a dark brownish gray, along with glaucous, testaceous, and ochraceous. Field description needs a dozen names for brown, and Latin supplied them.
Notes
The ferruginous hawk is the largest hawk in North America, a bird of open western grassland with rust-colored legs and shoulders. The ferruginous duck of Eurasia and the ferruginous pygmy owl of the Americas carry the same description. In each case the name marks a specific warm rust rather than any brown.