This fact, allied to being species that are easy to grow and to identify, make them a favorite of orchid collectors all over the world.
Despite the fact that Miltonia is now a well established genus, most of its species were originally classified under other genera as Cyrtochilum, Oncidium, Odontoglossum, and Brassia.
They are named after Charles Wentworth-Fitzwilliam, 5th Earl Fitzwilliam, formerly Viscount Milton, an English aristocrat, politician, patron of science and horticulture, and orchid enthusiast.
Miltonia are comparatively medium large orchid plants reaching about fifty centimeters height.
They present subcaespitous growth, that means their pseudobulbs are not tightly packed but slightly spaced by a rhizome, that is longer than on caespitous plants, with length between two and five centimeters.
They may be more oval and laterally highly flattened to slightly tetragonal and elongated and almost always bear two apical leaves.
The leaves are narrow, flexible and hardly larger than three centimeters wide and forty long with the apexes rounded sometimes slightly pointed.
The labellum is simple or very slightly lobed, usually very wide and showy without salient calli although normally showing more or less subtle keeled thickenings close to the base, usually of different colors; it is much larger and wider than the other segments, often flat but in M. candida embraces the column and in all species it is slightly fused to the column at their bases.
The short column does not have a foot and presents two lateral auricles sometimes merged to each other through a fringe that surrounds the superior edge of the clinandrium.
[9] The first species to be described, among the ones today classified under the genus Miltonia, was originally published by John Lindley, in 1834, as Cyrtochilum flavescens.
[10] Two years later Lindley described another Miltonia species but, then, under the genus Oncidium, as O. russellianum in homage to Duke of Bedford.
When describing this plant, Lindley considered it as a transition species pointing out that it was very different from the average Oncidium because of its purple colors and undivided lip.
Recognizing then this should in fact be a new genus, he proposed the name Miltonia to it as a homage to Charles Wentworth-Fitzwilliam, 5th Earl Fitzwilliam, formerly Viscount Milton, an English orchid enthusiast.
[17] Despite the early description of M. moreliana in 1848, and two other as M. rosea by Lemaire in 1867,[18] and as M. warneri by George Nicholson in 1886,[19] Arthur Henfrey reduced it to a variety of Miltonia spectabilis in 1851,[20] and as such it was considered until 2002, when Cássio van den Berg reestablished it as a distinct species.
[21] The last Miltonia species to be discovered was M. kayasimae,[needs update] found by an orchid collector not far from the city of São Paulo, in an area around nine hundred meters of altitude nearby the top of Serra do Mar mountains.
[25] These are species of more delicate and narrower flowers, from Mexico and Central America, which some taxonomists claim might be better classified under the genus Oncidium to whom they are closely related.
[15] In 2001, based on molecular analysis, Norris Williams and Mark Chase, transferred a species previously classified under the genus Oncidium, as O. phymatochilum, to Miltonia.
[22] Miltonia clowesii has the same color pattern of M. russelliana with light yellow greenish brown sepals and petals completely covered with large darker dots or stains and labellum of bright purple at the base and lighter apex, however here they are whiter.
On the other hand, M. clowesii flowers' pointed segments are larger and wide opened making it resemble a spider.
They are always epiphyte and, because they grow very fast, each pseudobulb originating two new growths every year, they soon form large colonies.
M. kayasimae is the only species really rare; it has been found just a couple of times in a very restricted area close to Salesópolis, in São Paulo State.
The mountains area between São Paulo and Rio de Janeiro, where almost all species do exist may be considered the center of distribution of Miltonia.
Finding the right balance of light exposure to avoid yellow leaves but still produce nice blooming is important and with some precautions the grower will succeed.