chlamydeous

Probably back-formation from achlamydeous, archichlamydeous, metachlamydeous, monochlamydeous; or from Ancient Greek χλᾰμῠ́δ- (khlămŭ́d-, stem of χλᾰμῠ́ς (khlămŭ́s)) chlamys + -eous.

来源：wiktionary