Many species used to be classified in the genus Maxillaria although in the 19th century it was already noted that there are clear physiological differences. Genetic research shows the differences justify a separate genus.
The type species is Ornithidium coccineum.
The genus Ornithidium is distinguished by the labellum which is partially merged with the column, a tapered column, an anther with only two valves and pollen which is matted to a gland.
Laricorchis, Maxillaria sect. Ornithidium, Maxillaria sect. Reflexae, Maxillaria, Neourbania, Siagonanthus
Ornithidium: from the Greek órnis (bird) and -idiom (diminutive suffix)
Caribbean, from Mexico to Bolivia