Miltonia, abbreviated Milt. in the horticultural trade, is an orchid genus comprising twelve epiphyte species and eight natural hybrids. The miltonias are exclusively inhabitants of Brazil, except for one species whose range extends from Brazil into the northeast of Argentina and the east of Paraguay.
The genus of Miltonia was established by John Lindley in 1837, when he described its type species, Miltonia spectabilis. Formerly many more species were attributed to Miltonia, however, beginning in 1978, the miltonias from Central America and from cooler areas of northwest South America have been moved to other genera, including Miltoniopsis and Oncidium, and these changes are still in the process of being accepted by the horticultural trade.
Miltonia species have large and long lasting flowers, often in multifloral inflorescences. 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. Species of this genus are extensively used to produce artificial hybrids.
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. All were discovered between 1834 and 1850 with the exception of M. kayasimae, discovered only in 1976.
These orchids have two leaves, arising from a pseudobulb, covered with a foliaceous sheath. The inflorescence consists of waxy, nonspurred flowers. The lip is large and flat and lacks a callus at its base. They possess a footless column with two hard pollinia. The flowers have a delicate, exotic scent, some compare to that of roses.
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.
The species in this genus are sometimes referred to as the pansy orchids, but it is the Miltoniopsis orchids that have flowers that closely resemble the pansy. Almost everyone except for the most serious orchid hobbyists uses the name pansy orchids interchangeably, which may cause confusion.
Miltonia looks more like Oncidiums than the other pansy orchids. The most "pansy-like" a Miltonia can get is the species Miltonia spectabilis. Taxonomists are debating whether to combine Miltonia with the genus Oncidium because of the many connections between the two.
Miltoniopsis is the pansy orchid with huge showy flowers. They grow in cooler climates and are more challenging to grow than Miltonia.
This genus forms with Miltoniopsis a hybrid genus ×Milmiltonia J.M.H.Shaw.
Description
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. Their roots grow along the rhizome in high numbers. They are white, comparatively thin, usually short and hardly branched. The rhizome is covered by dried imbricating steaths which get increasingly larger at the base of pseudobulb becoming articulated foliar steaths that partially cover them. The pseudobulbs and leaves vary in color from yellowish bright light green to olive green depending on the species and to the amount of sunlight they are exposed to. 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. Some species are about half of this size. The inflorescences are one or two per pseudobulb, shoot from their bases behind the protecting steaths. They are erect and never branched, often longer than the leaves, bearing from one to twelve moderately spaced flowers that open at the same time or in succession holding three or four opened all the time, when the older fades a new one opens. The older flowers of species with white lips that open in succession usually get yellower about the time the next flower opens although they still last one more week before fading. The first to bloom is M. cuneata, during late winter, but the majority of species bloom from late spring to late summer.Cogniaux, Célestin Alfred (1903). Miltonia in Flora Brasiliensis 3-6: 267-286. K.F.P. von Martius Ed.. Published on Internet, in Latin.
The flowers of Miltonia vary from four to fifteen centimeters across; the larger are the ones with fewer flowers. Their colors vary from entirely white and pink to dark purple, pale yellow or lilac when plain, or they may highly spotted but then usually they are greenish or brownish with a contrasting labellum often white with purple dots, stains or veins close to the base. The petals and sepals shapes are highly variable from species to species but always somewhat similar to each other within a species. They may be erect and flat or sometimes less open. 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. The anther is apical and bears two yellow hard pollinia. They possibly are pollinated by bees.Hoehne, Frederico C. (1940). Introduction in Flora Brasílica, Vol 12-1: 37-8. Secretaria de Agricultura de São Paulo.
Taxonomy
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. In this description Lindley notices that the flowers of this species turn orange color when drying and, for some confusion regarding the origin of the species, attributes it to Mexico instead of Brazil.Lindley, John (1834). Cyrtochilum flavescens in Edwards's Botanical Register 19: t. 1627. England. 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.Lindley, John (1836). Oncidium russellianum in Edwards's Botanical Register 22: t. 1830. England.
In 1837, Lindley received from Mr. Loddiges and from George Baker two other specimens of a very distinctive new species. 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. Lindley states then that the limits between a number of Oncidiinae genera, Cyrtochilum, Oncidium, Odontoglossum, Brassia and Miltonia, at that time classified as Vandaea, were yet to be perfectly established; although closely related, the differences should possibly be: Oncidium has a column with two ears and labellum distinctively lobed; Miltonia has a column with two ears and an entire labellum partially united to the column base; Odontoglossum and Cyrtochilum have winged columns and entire labelli but the former has it partially united to the column; and Brassia does not have any appendages on the column. Although Lindley described the genus Aspasia (which is the most closely related to Miltonia) in 1833, both by flower and vegetative morphologies, he did not mention it on his Miltonia description.Lindley, John (1837). Miltonia spectabilis in Edwards's Botanical Register 23: t. 1992. England.
Three other botanists were working with Miltonia species around the time Lindley described this genus. All recognized these plants should be classified under a new genus and, as communications were slower then, all proposed new genera: Knowles and Westcott also received also a plant of M. spectabilis and, just one month after Lindley, proposed for it the genus Macrochilus, calling the species Macrochilus fryanus;Knowles, George B. & Westcott, Frederic (1837). Macrochilus fryanus in Floral Cabinet 1: 93. England. the other one was Rafinescque who, in 1838, decided that the Oncidium russellianum already described by Lindley in 1836 should be under another genus and created for it the genus Gynizodon.Rafinescque, Constantine S. (1838). Gynizodon russelliana in Flora Telluriana 4: 40.. Both Macrochilus and Gynizodon are synonyms of Miltonia and no other species has ever been submitted to them.
As Miltonia species are common plants, comparatively large, with also large flowers of bright colors, that, moreover, are spread mostly over an area of early settlements in Brazil all species but one were already described in 1850; six of them by Lindley, M. regnellii by ReichenbachReichenbach, Heinrich G. (1850). Miltonia regnellii in Linnaea 22:: 851. and M. moreliana by Achille Richard.Richard, Achille (1848). Miltonia moreliana in A.Rich., Portef. Hortic. 2: 38. Despite the early description of M. moreliana in 1848, and two other as M. rosea by Lemaire in 1867,Lemaire, Charles (1867). Miltonia rosea in Ill. Hort. 14.: t. 524. and as M. warneri by George Nicholson in 1886,Nicholson, George (1886). Miltonia warneri in Ill. Dict. Gard. 2: 369. Arthur Henfrey reduced it to a variety of Miltonia spectabilis in 1851,Henfrey, Arthur (1851). Miltonia spectabilis var. moreliana in Gard. Mag. 3:: 41. London. and as such it was considered until 2002, when Cássio van den Berg reestablished it as a distinct species.Carlini-Garcia, L. A..; C. van den Berg; P. S. Martins (2002). A morphometric analysis of floral characters in Miltonia spectabilis and M. spectabilis var. moreliana. Lindleyana 17(3): 122-129. Published on Internet. The last Miltonia species to be discovered was M. kayasimae, 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. It was named after their collector by Guido Pabst in 1976. So far very few plants were found, all living at the same area.Pabst, Guido F.J. (1976). Miltonia kayasimae in Bradea 2: 88.