The Collaborative International Dictionary
Rubiginose
Rubiginose \Ru*big"i*nose`\, Rubiginous \Ru*big"i*nous\, a. [L. rubiginosus, fr. rubigo, robigo, rust: cf. F. rubigineux.] (Bot.) Having the appearance or color of iron rust; rusty-looking.
Wiktionary
rubiginose
a. (context botany English) Having the appearance or colour of iron rust; rusty-looking.