× Miltonidium, abbreviated as Mtdm. in the horticultural trade,[1] is the nothogenus for hybrids between the orchid genera Miltonia and Oncidium (Milt. × Onc.). An example is Miltonidium Purple Sunset, which is a hybrid of Miltonia Victoria and Oncidium hastilabium.[2]
When Cochlioda and Odontoglossum are sunk into Oncidium, and other parents remain in Miltonia, × Burrageara, × Colmanara, × Odontonia and × Vuylstekeara become synonyms.
The nothogenus (hybrid genus) name × Miltonidium was first published in 1936, for hybrids between Miltonia and Oncidium. The first hybrid registered in this nothogenus was × Miltonidium Aristocrat in 1940., both of its parents were placed in Oncidium so the correct name of the grex became Oncidium Aristocrat.
Other changes to the circumscription of the genus Oncidium have caused changes to the nomenclature of nothogenera. The genus Gomesa has been split off from Oncidium. Several grexes formerly treated as Miltonia × Oncidium and so placed in × Miltonidium have now become Gomesa × Miltonia = × Gomonia. For example, Gomonia Mateus Pomini Uel, generated from Miltonia regnellii × Gomesa imperatoris-maximiliani, two native Brazilian orchids, was placed in × Miltonidium[3] when Gomesa imperatoris-maximiliani was known by its synonym Oncidium imperatoris-maximiliani.[4]
, Plants of the World Online sank Cochlioda and Odontoglossum within Oncidium. Some other nothogenera then have the same parent genera as × Brassidium.
× Burrageara, abbreviated Burr. in the horticultural trade, is the nothogenus for hybrids between the orchid genera Cochlioda, Miltonia, Odontoglossum and Oncidium. It was grown for the first time by the American Albert Burrage in 1927, and named after him. When Cochlioda and Odontoglossum are synonymized with Oncidium, the parents of × Burrageara become just Miltonia and Oncidium. For example, the grex name × Burrageara Helen Kelley is a synonym of × Miltonidium Helen Kelley. Its parents include Oncidium hastatum and Oncidium noezlianum, previously placed in Odontoglossum and Cochlioda respectively.[5] [6]
× Miltonidium Candy Harry is a hybrid between Miltonia candida and Oncidium harryanum. The latter was previously known as Odontoglossum harryanum,[7] so the hybrid was known by the synonym × Odontonia Candy Harry.