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These articles were originally printed in 1993 in the American Orchid Society Bulletin, part one 62(8):794-799, and part two 62(9):901-908.
Charles and Margaret Baker
The genus Miltoniopsis was established in 1889 by Godefroy-Lebeuf, but it was not generally accepted until 1976, when it was resurrected by Garay and Dunsterville. At that time, they described a new species, M. santanaei, and moved the other Andean and Central American species into the reinstated genus. To round out the genus as it now stands, in 1989 Dodson and Bennett described M. bismarckii, a new species from Peru. The genus Miltoniopsis presently includes M. phalaenopsis, M. roezlii, M. vexillaria, M. bismarckii, M. santanaei, and M. warscewiczii.
Garay and Dunsterville describe the technical differences between Miltonia and Miltoniopsis, but garden variety growers can easily distinguish between the two genera, as Miltoniopsis has 1-leaved rather than the 2-leaved pseudobulbs of Miltonia. Also, the flattened pseudobulbs of Miltoniopsis are tightly clustered while those of most Miltonia are widely separated by a long rhizome. The genus Miltoniopsis is presently used and accepted by most of the orchid community, but hybrids are still registered under the name Miltonia, as four of the six species were previously classified in that genus. Over the years, growers have referred to these species, along with their hybrids, as the "cool growing" or "Colombian" Miltonias, or the "pansy orchids". These names are still used by some growers, although the species are not necessarily found in Colombia, nor are they particularly cool growing except for M. warscewiczii which grows in Costa Rica and Panama.
Unfortunately, Miltoniopsis have developed a reputation as being "difficult", "not a beginner's plant", and have been tagged with various other lables indicating that people have had trouble growing them. As a result, many people do not even try to grow them. Despite their reputation, they are relatively easy to grow if their few particular requirements can be met. Successful growers are rewarded with 2-3 spikes of large, lovely, usually fragrant blossoms from each new growth. The flowers last 4-8 weeks on the plant, but they are short-lived as cut flowers. Well grown plants often produce a second flowering several months after the primary bloom season. Consequently, a plant may be in bloom much of the year.
The following cultural information is generally appropriate for both hybrids and species. In a later article, the specific cultural requirements for each species will be reviewed.
ORIGIN/HABITAT: The three species that have been primarily used in developing the modern hybrids are found in Colombia, Ecuador, and Panama. They grow in locations that range from hot, humid lowlands for M. roezlii, to relatively cool, humid cloudforests forM. vexillaria, while M. phalaenopsis is found in humid forests about halfway between these extremes. The operative word in all cases is humid, as moisture is available most of the year from rainfall, mist, or heavy deposits of dew.
LIGHT: 1000-2000 fc. For those without light meters, this is not deep shade, but is enough shade so that no shadow results when a hand is passed between the plant and the light source. It is about the same amount of light required by many Paphiopedilums, and a little less than needed by Cattleyas. Because the light requirement is low, Miltoniopsis are easy to grow under artificial lights if humidity is moderately high.
Miltoniopsis produce the most blooms when they receive as much light as they can tolerate without causing damage to the foliage. A slight pinkish tinge on the leaves indicates correct light levels, while red, yellow, or straw colored leaves indicate that light is too high. The sepals and petals of some Miltoniopsis tend to recurve when light is high. Flower quality often improves if plants are moved to lower light after the buds develop.
TEMPERATURES: Season temperature variation is minor. Days should average 80-85°F (27-29°C), and nights should average 60-64°F (16-18°C), with a diurnal range of about 20°F (11°C). Plants can tolerate temperatures higher than 90°F (32°C) for brief periods, especially if humidity is high and air movement is strong. Some growers successfully cultivate Miltoniopsis with Phalaenopsis at night temperatures near 68°F (20°C). Other growers report success cultivating plants with Cattleyas at 55-58°F (13-14°C). Although this appears confusing, it represents the range of temperatures found in the habitats of the three species used to develop the modern hybrids. However, we have found that our hybrids produce more and larger growths and more flowers if night temperatures do not fall below 60°F (16°C).
HUMIDITY: Daily humidity should average 70-80%, with late night maximums of 80-90% and afternoon minimums of 50-60%. If high winter humidity creates problems with condensation, humidity may be reduced slightly. However, strong air movement prevents condensation, even when humidity is high.
WATER: All Miltoniopsis species and their hybrids need to be kept evenly moist. They should never be allowed to dry out completely. This "evenly moist" instruction is not a phrase intended to keep beginners confused and feeling like outsiders. Rather, it is an attempt to describe a concept that new growers often find difficult to grasp when all they really want is an answer the deceptively simple question, "How often should I water this thing?"
Unfortunately, it is not a simple question. In fact, so many variables enter into determining watering frequency that there is no way it can be accurately answered. Some of the elements that influence watering frequency include the season, the average temperature and humidity both outdoors and inside the growing area, the day length, whether skies have been clear or cloudy, the type of medium used, the type of pot used, the size of the pot, how long since the plant was repotted, and the strength of air movement in the growing area. Consequently, each grower must learn to determine when their plant needs water. Some of the tried and true methods include lifting the pot and judging the weight, working a finger into the medium to feel for moisture, or simply judgement and experience.
Obviously, it is impossible to keep a plant evenly moist. The degree of wetness varies depending on when it was last watered, and as soon as the moisture varies, it is no longer evenly moist. Thus, new growers perceive a catch 22. Generally it means that the plant should always be kept damp, but not soggy. One explanation we found helpful suggests that evenly moist means that the plant should be watered today if the grower feels it will need to be watered tomorrow. Unfortunately, the grower is still left with the frustrating task of determining if the plant will need to be watered tomorrow.
In our growing area, adult Miltoniopsis in 4-5 in. (10-13 cm) pots which are filled with our fir bark mix are usually sufficiently moist when they are watered 2-3 times a week from spring into autumn. During very hot, dry periods in summer, however, plants may require daily watering. However, during our often damp, dreary winter weather, plants may need to be watered as infrequently as once every 2-3 weeks.
The only time Miltoniopsis should be slightly drier is immediately after potting, especially if they are repotted before new roots are growing. Regular watering should be resumed as soon as new roots begin to enter the fresh medium.
FERTILIZER: 1/4-1/2 recommended strength, applied weekly while the plants are actively growing. Most growers prefer to use a fertilizer high in nitrogen, such as 30-10-10, most of the time. However, once every 3-4 weeks, they recommend a fertilizer with less nitrogen and more phosphate such as 10-20-10. The periodic use of a high-phosphate fertilizer improves flowering.
Growers sometimes have a problem with die-back on the tips of mature leaves. While this condition may result from a lack of water, it usually indicates that excessive salts are accumulating in the potting medium. Salt buildup can result from over fertilizing or using heavily mineralized water. To prevent this condition, pots should be leached every few weeks especially when fertilizer is being applied most heavily. Plants should first be watered normally to dissolve the accumulated salts. An hour or so later, the medium should be flushed with water equal to about twice the volume of the pot. Year-round leaching is important in areas with heavily mineralized water.
REST PERIOD: Growing conditions should be maintained year-round. It is important to provide a 10-20°F (6-11°C) range between daily high and low temperatures. Water should be reduced slightly in winter, especially for plants grown in the dark, short-day conditions common in temperate latitudes, or if night temperatures in the growing area are cooler than 60°F (16°C). The plants simply do use as much water when light is low, days are short, or temperatures are cool. However, plants should never be allowed to dry out completely. If water is reduced, fertilizer should also be reduced until plants begin growing the next spring.
GROWING MEDIA: The fine, threadlike roots of Miltoniopsis plants are easily killed if the medium is too dry or too wet and soggy. The medium must drain well while remaining moist. Most growers prefer a fine-grade fir bark mixed with moisture retaining materials such as perlite or chopped sphagnum moss. In addition, some growers add materials such as charcoal, crushed oyster shells, peanut hulls, rice hulls, coarse peat moss, or shredded tree-fern fiber to their mix. These additives vary depending on the growers watering practices and the general conditions in the growing area.
Plastic pots are usually preferred since they retain more moisture, but drainage must be excellent. A layer of coarse bark in the bottom of the pot improves drainage. Also, drainage holes in plastic pots may be enlarged and extra ones added by melting with a hot soldering iron. The fumes from the melting plastic may be toxic, so this particular task should be done out-of-doors or in a well ventilated area.
Miltoniopsis are healthiest when repotted every year. Next to simply providing the basic requirements, annual repotting is probably the single most important action a grower can take to ensure success. Do not over pot! Plants should be placed in a small pot that is barely large enough to contain the roots and allow room for another year's growth. When repotting, do not simply "pot on" into a larger pot, leaving the rootball with the old, stale medium intact. All old medium should be removed, any damaged or diseased roots trimmed off, and the plant repotted using all fresh medium and a clean pot. Repotting is best done in autumn when new root growth begins, usually when the newest growths are about half mature. Repotting by early winter allows the plant time to become reestablished before the stress of hot, summer weather.
MISCELLANEOUS NOTES: Miltoniopsis leaves are particularly good at communication if growers learn what they are indicating. They tell us when light levels are correct (a slight pinkish tinge), when light is too high (a red, tan, or straw color), if salts are building up in the medium (leaf-tip die-back), and if humidity is too low or water is insufficient (horizontal accordion folds on the developing leaves of immature growths). Once present, these folds remain for the life of the leaf as a constant reminder to the grower and everyone else who sees them that at least once the grower was remiss.
If watering practices and humidity levels are correct and the leaves still fold and crinkle as new growth develops, it is probably an indication of root rot. This disease is usually caused by overwatering, especially in old, stale medium. Root rot prevents the plant from utilizing the water it needs and often causes the same symptoms that indicate underwatering. If this problem occurs, the plant should be repotted immediately in a clean pot with fresh medium. Before repotting, the dark, soft, diseased roots should be trimmed off. The plant should then be soaked for an hour or so in a natriphene solution mixed at 3/4 teaspoon per gallon.
These general cultural recommendations should give growers who have been wary of Miltoniopsis the confidence to give them a try. Well grown plants soon begin producing multiple growths, each with several inflorescences. They are spectacular when in full bloom.
If Miltoniopsis hybrids are considered difficult to cultivate, the species are usually thought to be even more challenging. However, many growers find both species and hybrids easy to grow providing their particular needs are met. The species are so charming and rewarding that they should be given a chance by more growers. Many of cultural requirements, such as water, humidity, fertilizer, and growing media, were discussed for Miltoniopsis hybrids in Part 1, and generally apply to the species as well. However, the species have a few specific needs and differing temperature requirements as indicated in the following climate data, which is representative of the weather in each species' habitat.
Miltoniopsis bismarckii Dodson & Bennett. The light green plants are 7-8 in. (18-20 cm) tall. New growths often produce two inflorescences and each carries 4-6 flowers. The blossoms, which open flat, are about 1.6 in. (4 cm) across. They have light rose-pink sepals, darker petals, and a dark rose-purple lip. The lip has a yellow disk marked with ochre-red spots.
This new species was discovered by Klaus von Bismarck in 1985 and described in 1989 by Dodson & Bennett. A few years ago, a number of plants were exported from Peru. They were sold as M. vexillaria, so some plants may be incorrectly labeled.
ORIGIN/HABITAT: Endemic to Peru. M. bismarckii was discovered in the Department of Huanuco growing in wet, tropical forests of the Cordillera Azul at 3300 ft. (1005 m).
CLIMATE: Station # 84534, Tingo Maria, Peru, Lat. 9.1°S, Long. 75.9°W, at 2106 ft. (642 m). Temperatures are calculated for an elevation of 3300 ft. (1005 m), resulting in probable extremes of 93°F (34°C) and 35°F (2°C).
N/HEMISPHERE JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC F AVG MAX 82 84 84 83 83 83 82 81 82 82 83 82 F AVG MIN 59 60 60 61 61 62 62 62 62 62 61 60 DIURNAL RANGE 23 24 24 22 22 21 20 19 20 20 22 22 RAIN/INCHES 5.8 8.2 8.0 15.9 24.9 12.0 15.9 16.4 22.8 8.5 8.7 4.5 HUMIDITY/% N/A BLOOM SEASON * * * DAYS CLR @ 7AM 2 3 3 1 1 1 0 0 0 1 1 1 DAYS CLR @ 1PM 15 12 9 3 4 4 4 1 4 2 7 12 RAIN/MM 147 208 203 404 632 305 404 417 579 216 221 114 C AVG MAX 27.8 28.9 28.9 28.4 28.4 28.4 27.8 27.3 27.8 27.8 28.4 27.8 C AVG MIN 15.0 15.6 15.6 16.1 16.1 16.7 16.7 16.7 16.7 16.7 16.1 15.6 DIURNAL RANGE 12.8 13.3 13.3 12.3 12.3 11.7 11.1 10.6 11.1 11.1 12.3 12.2 S/HEMISPHERE JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN
LIGHT: 1200-2000 fc.
TEMPERATURES: Throughout the year, days average 81-84°F (27-29°C), and nights average 59-62°F (15-17°C), with a diurnal range of 19-24°F (11-13°C).
MISCELLANEOUS NOTES: The bloom season shown in the climate table is based on reports from the habitat.
Miltoniopsis phalaenopsis (Linden & Rchb.f.) Garay & Dunsterville. The plant is 6-12 in. (15-30 cm) tall. The inflorescences, which are shorter than the leaves, carry 3-5 flat blossoms 2.0-2.5 in. (5.0-6.5 cm) across. All segments are white, but the lip is marked with light purple streaks and blotches.
In the past, plants have been known as Odontoglossum phalaenopsis Linden & Rchb. f. and Miltonia phalaenopsis (Linden & Rchb.f.) Nicholson.
ORIGIN/HABITAT: Originally found in central Colombia on the western slopes of the Cordillera Oriental near Ocãna. Plants also grow near Velez, where they are found in humid, temperate forests at 3950-4900 ft. (1200-1500 m).
CLIMATE: Station # 80094, Palonegro, Colombia, Lat. 7.1°N, Long. 73.2°W, at 3937 ft. (1200 m). Temperatures are calculated for an elevation of 4500 ft. (1370 m). Record extreme temperatures are not available for this location.
N/HEMISPHERE JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC F AVG MAX 74 75 75 74 75 75 75 76 76 74 74 74 F AVG MIN 64 64 65 64 64 64 64 64 63 63 63 63 DIURNAL RANGE 10 11 10 10 11 11 11 12 13 11 11 11 RAIN/INCHES 0.8 1.5 1.6 3.6 3.0 1.8 2.2 2.4 2.5 2.6 3.7 1.1 HUMIDITY/% N/A BLOOM SEASON * * ** *** ** * * * * * DAYS CLR N/A RAIN/MM 20 38 41 91 76 46 56 61 64 66 94 28 C AVG MAX 23.4 24.0 24.0 23.4 24.0 24.0 24.0 24.5 24.5 23.4 23.4 23.4 C AVG MIN 17.9 17.9 18.4 17.9 17.9 17.9 17.9 17.9 17.3 17.3 17.3 17.3 DIURNAL RANGE 5.5 6.1 5.6 5.5 6.1 6.1 6.1 6.6 7.2 6.1 6.1 6.1 S/HEMISPHERE JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN
LIGHT: 1500-2000 fc.
TEMPERATURES: Throughout the year, days average 74-76°F (23-25°C), and nights average 63-65°F (17-18°C), with a diurnal range of 10-13°F (6-7°C).
WATER: Rainfall is relatively constant through most of the year, with a 2-3 month drier period in winter. Moisture is more available in the microclimate than is indicated by the average rainfall amounts. Growers report that M. phalaenopsis requires a drier rest than M. vexillaria, so water should be reduced a little more in winter. However, the plants should never be allowed to dry out completely.
MISCELLANEOUS NOTES: The bloom season shown in the climate table is based on cultivation records. Because of its relatively smaller flowers, M. phalaenopsis has not been used as frequently as M. roezlii and M. vexillaria in creating the modern Miltoniopsis hybrids. When used, however, it contributes the lovely purple mask to its progeny. In addition, M. phalaenopsis and the 'Memoria G. D. Owen' cultivar of M. vexillaria are responsible for the "waterfall" and "teardrop" patterns on the lips of many of today's popular hybrids.
Miltoniopsis roezlii (Rchb.f.) Godefroy-Lebeuf. The light bluish-green plant is 11-15 in. (28-38 cm) tall. New growths produce 1-2 slender inflorescences about 12 in. (30 cm) long which carry 2-5 flat blossoms. The flowers are 3-4 in. (7-10 cm) across. They are white with a purple blotch at the base of each petal and an orange-yellow disk at the base of the lip. They are delightfully fragrant.
In the past, plants have been known as Odontoglossum roezlii Rchb.f. and Miltonia roezlii (Rchb.f.) Nicholson.
ORIGIN/HABITAT: Dagua River Valley of northwest Colombia. Plants grow in warm, humid habitats at 1000-3300 ft. (300-1000 m). M. rozellii also grows in the coastal mountains of extreme southwest Panama. This is the warmest growing Miltoniopsis species.
CLIMATE: Station # 80144, Quibdo, Colombia, Lat. 5.7°N, Long. 76.6°W at 177 ft. (54 m). Temperatures are calculated for an elevation of 2000 ft. (610 m). Extreme temperatures are not available for this location.
N/HEMISPHERE JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC F AVG MAX 77 77 78 79 79 79 80 80 80 79 78 77 F AVG MIN 68 68 68 69 68 69 68 68 68 67 67 67 DIURNAL RANGE 9 9 10 10 11 10 12 12 12 12 11 10 RAIN/INCHES 3.8 7.3 6.8 8.7 7.1 7.7 8.8 9.1 13.0 9.6 11.0 8.1 HUMIDITY/% N/A BLOOM SEASON * * ** ** *** ** ** ** ** ** * * DAYS CLR N/A RAIN/MM 97 185 173 221 180 196 224 231 330 244 279 206 C AVG MAX 25.0 25.0 25.5 26.1 26.1 26.1 26.7 26.7 26.7 26.1 25.5 25.0 C AVG MIN 20.0 20.0 20.0 20.5 20.0 20.5 20.0 20.0 20.0 19.4 19.4 19.4 DIURNAL RANGE 5.0 5.0 5.6 5.6 6.1 5.6 6.7 6.7 6.7 6.7 6.1 5.6 S/HEMISPHERE JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN
LIGHT: 1500-2500 fc.
TEMPERATURES: Throughout the year, days average 77-80°F (25-27°C), and nights average 67-69°F (19-21°C), with a diurnal range of 9-12°F (5-7°C). However, growers indicate that M. roezlii adapts to cooler night temperatures of 60-64°F (16-18°C). Plants tolerate warmer daytime temperatures for short periods, especially if high humidity and strong air movement are maintained. Temperatures above 100°F (38°C) may cause the plants to appear unhealthy, but they usually recover when temperatures cool. During hot summer months, plants are healthiest if placed near an evaporative cooler.
MISCELLANEOUS NOTES: The bloom season shown in the climate table is based on cultivation records. The primary bloom season is spring, but well grown plants may bloom again in autumn. M. roezlii has been used extensively to develop the modern Miltoniopsis hybrids. It is frequently crossed with M. Phalaenopsis and M. vexillaria. Seed capsules mature sufficiently for green pod culture 6-8 months after pollination.
Miltoniopsis santanaei Garay & Dunsterville. The pale green plant is about 11 in. (27 cm) tall. The inflorescences are about 4 in. (10 cm) long and carry 2 or more blossoms. The flowers are about 2 in. (5 cm) across. Sepals and petals are white with a yellow or greenish tinge at the base. The white lip is marked with a kidney shaped patch of yellow near the base and 5, slightly raised purple nerves.
In the past, plants have been known as Miltonia roezlii var. alba (Hort.) B. S. Williams.
ORIGIN/HABITAT: Found in Venezuela, Colombia, and Ecuador. In Venezuela, plants grow about 37 mi. (60 km) north of Tumeremo in the northeastern part of the country. They inhabit damp forests near 1950 ft. (600 m). In Ecuador, plants are found on both sides of the Andes, where they grow epiphytically in mountain cloudforests at 1150-3300 ft. (350-1000 m.)
CLIMATE: Station # 80453, Tumeremo, Venezuela, Lat. 7.3°N, Long. 61.2°W, at 614 ft. (187 m). Temperatures are calculated for an elevation of 1950 ft. (600 m), resulting in probable extremes of 97°F (36°C) and 54°F (12°C).
N/HEMISPHERE JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC F AVG MAX 82 83 85 86 85 83 84 86 87 87 86 83 F AVG MIN 64 64 64 65 67 66 65 66 66 66 66 65 DIURNAL RANGE 18 19 21 21 18 17 19 20 21 21 20 18 RAIN/INCHES 3.9 3.0 2.4 3.0 6.1 7.2 6.0 4.9 3.0 2.2 2.5 4.4 HUMIDITY/% 87 85 82 81 84 88 86 84 81 81 84 86 BLOOM SEASON * * ** ** * ** ** * * ** * DAYS CLR @ 7AM 2 0 1 1 1 1 1 2 1 1 1 1 DAYS CLR @ 1PM 0 0 0 0 0 0 0 0 0 0 0 0 RAIN/MM 99 76 61 76 155 183 152 124 76 56 64 112 C AVG MAX 27.6 28.1 29.2 29.8 29.2 28.1 28.7 29.8 30.3 30.3 29.8 28.1 C AVG MIN 17.6 17.6 17.6 18.1 19.2 18.7 18.1 18.7 18.7 18.7 18.7 18.1 DIURNAL RANGE 10.0 10.5 11.6 11.7 10.0 9.4 10.6 11.1 11.6 11.6 11.1 10.0 S/HEMISPHERE JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN
LIGHT: 1500-2000 fc.
TEMPERATURES: Throughout the year, days average 82-87°F (28-30°C), and nights average 64-67°F (18-19°C), with a diurnal range of 17-21°F (9-12°C).
MISCELLANEOUS NOTES: The bloom season shown in the climate table is based on cultivation records. Chromosome counts are 2n = 56 and 2n = 60 as M. roezelii var. alba. M. santanaei is rarely used in hybridizing.
Miltoniopsis vexillaria (Rchb.f.) Godefroy-Lebeuf. The pale green plants are about 12 in. (30 cm) tall. Inflorescences are about 12 in. (30 cm) long and carry about 4 blossoms. The large, showy flowers are 2-4 in. (5-10 cm) across. They may be pink, often with white margins on the segments, or they may be white, sometimes with a pink flush or pink stripes. The lip, which has yellow markings at the base, is also marked with maroon stripes and blotches. The blossoms are very flat.
In the past, plants have been known as Odontoglossum vexillarium Rchb.f. and Miltonia vexillaria (Rchb.f.) Nicholson.
ORIGIN/HABITAT: Colombia and Ecuador. Originally discovered in Colombia, M. vexillaria is found in isolated patches in the central mountain region and on the western slopes of the Cordillera Occidental from the province of Antioquia southward into Ecuador. Plants usually grow on the margins of very wet mountain forests at 4250-7050 ft. (1300-2150 m). Although found in many Colombian locations, M. vexillaria occurs in moderate numbers in the cool mountains of Antioquia and Caldas. Veitch (1887-1894), included the following description of the habitat of M. vexillaria. It was given by Herr F. C. Lehmann, the German Consul to Colombia at the time. Lehmann reported that, "With one exception, the variety albicans which occurs at 4000-5000 feet along the river Cuaiquer, the lower and higher limits of Miltonia vexillaria are almost everywhere about 4750 and 6500 feet above sea-level." He went on to report that, "Miltonia vexillaria is found isolated in places influenced by local climatic conditions, being most abundant at its medium altitude; it always occurs on the borders of the denser mountain forests which have below them either open or park-like stretches covered with low bushes or coarse savannah grass, and above, the extremely humid and almost impenetrable and luxuriant forests that cover the Cordilleras at that altitude. The characteristic hygrometric peculiarity of the whole region over which Miltonia vexillaria is spread is, that it is constant nearly throughout the year; even in what is called the dry season the air is only relatively less humid. The daily changes in the weather may be thus summarized: - During the dry season the day breaks clear, but soon after sunrise a thick mist settles over the forest till about 10 a.m.; it then ascends higher, and the rays of the sun begin with difficulty to penetrate it; the air is then filled with a bluish mist that shuts out the distant view. A light shower of rain falls in the afternoon about 2 o'clock, which often continues till evening, when it gives place to a thick mist. During the rains there is generally a light wind blowing towards the mountains from the lower river valleys. In the rainy season the circumstances are nearly the same, except that the rain is more copious, the drops heavier, and the showers of longer duration."
CLIMATE: Station # 80110, Medellin, Colombia, Lat. 6.2°N, Long. 75.6°W, at 4916 ft. (1498 m). Temperatures are calculated for an elevation of 5600 ft. (1710 m), resulting in probable extremes of 90°F (32°C) and 39°F (4°C).
N/HEMISPHERE JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC F AVG MAX 80 80 82 80 80 80 81 80 80 78 79 79 F AVG MIN 57 58 57 58 58 56 57 58 58 58 58 59 DIURNAL RANGE 23 22 25 22 22 24 24 22 22 20 21 20 RAIN/INCHES 2.7 3.5 3.3 6.5 7.7 5.5 4.1 4.6 6.2 6.7 5.2 2.5 HUMIDITY/% 69 70 72 74 75 73 69 69 73 77 77 72 BLOOM SEASON * * * ** *** *** ** ** * * * * DAYS CLR @ 7AM 0 1 0 0 0 1 1 0 0 0 0 1 DAYS CLR @ 1PM 2 3 0 0 1 1 1 0 1 0 0 1 RAIN/MM 69 89 84 165 196 140 104 117 157 170 132 64 C AVG MAX 26.5 26.5 27.6 26.5 26.5 26.5 27.1 26.5 26.5 25.4 26.0 26.0 C AVG MIN 13.7 14.3 13.7 14.3 14.3 13.2 13.7 14.3 14.3 14.3 14.3 14.9 DIURNAL RANGE 12.8 12.2 13.9 12.2 12.2 13.3 13.4 12.2 12.2 11.1 11.7 11.1 S/HEMISPHERE JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN
LIGHT: 1800-2500 fc.
TEMPERATURES: Throughout the year, days average 78-82°F (25-28°C), and nights average 57-59°F (14-15°C), with a diurnal range of 20-25°F (11-14°C).
MISCELLANEOUS NOTES: The bloom season shown in the climate table is based on cultivation records. Chromosome count is 2n = 60. M. vexillaria is the primary parent in most modern hybrids.
Miltoniopsis warscewiczii (Rchb.f.) Garay & Dunsterville. The pale green plant is 10-14 in. (25-35 cm) tall. Each new growth may produce several inflorescences, which are 11-13 in. (28-33 cm) long and carry 3-5 flowers. The flat blossoms are about 2-3 in. (5-8 cm) across. Flowers are white with faint reddish-purple blotchs near the base of the segments. The lip has a hairy yellow callus with 3 short ridges in front.
In the past, plants have been known as Odontoglossum warscewiczii Rchb.f., Odontoglossum warscewiczianum Rchb.f. ex Hemsley, Miltonia endresii Nicholson, and Miltonia superba Schlechter. (Growers should be aware that there is still a valid species known as Miltonia warscewiczii Rchb.f.)
ORIGIN/HABITAT: Costa Rica and Panama. M. warscewiczii was originally found in Costa Rica growing epiphytically at 4600-6550 ft. (1400-2000 m). Plants have since been found in northern Panama growing at about the same elevation. This is the coolest growing Miltoniopsis species.
CLIMATE: Station # 78762, San Jose, Costa Rica, Lat. 10.0°N, Long. 84.2°W, at 3021 ft. (921 m). Temperatures are calculated for an elevation of 5600 ft. (1710 m), resulting in probable extremes of 83°F (29°C) and 40°F (5°C).
N/HEMISPHERE JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC F AVG MAX 66 67 70 70 71 70 68 69 70 68 68 66 F AVG MIN 49 49 50 53 53 53 53 52 52 51 51 49 DIURNAL RANGE 17 18 20 17 18 17 15 17 18 17 17 17 RAIN/INCHES 0.6 0.2 0.8 1.8 9.0 9.5 8.3 9.5 12.0 11.8 5.7 1.6 HUMIDITY/% 73 69 68 70 78 83 82 81 84 85 79 76 BLOOM SEASON ** ** ** * * * * * * ** DAYS CLR @ 6AM 5 8 11 2 1 0 0 0 2 1 2 3 DAYS CLR @ 12PM 5 4 8 3 0 0 0 0 0 0 0 1 RAIN/MM 15 5 20 46 229 241 211 241 305 300 145 41 C AVG MAX 19.2 19.7 21.4 21.4 21.9 21.4 20.3 20.8 21.4 20.3 20.3 19.2 C AVG MIN 9.7 9.7 10.3 11.9 11.9 11.9 11.9 11.4 11.4 10.8 10.8 9.7 DIURNAL RANGE 9.5 10.0 11.1 9.5 10.0 9.5 8.4 9.4 10.0 9.5 9.5 9.5 S/HEMISPHERE JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN
LIGHT: 1200-1800 fc. Growers report that M. warscewiczii needs more shade than other Miltoniopsis species.
TEMPERATURES: Summer days average 68-70°F (20-21°C), and nights average 53°F (12°C), with a diurnal range of 15-17°F (8-10°C). Conditions are slightly cooler in winter.
MISCELLANEOUS NOTES: The bloom season shown in the climate table is based on cultivation records. Chromosome count is 2n = 56. M. warscewiczii has not been used extensively for hybridizing, probably because progeny tend to resemble a poor quality M. roezlii in flower shape and growth habit. However, it should be valuable when breeding for increased cold tolerance.
Miltoniopsis species are seldom as gaudy as their modern hybrids. They do have their own special charm, however, and without them, hybrids would not be possible. Growers are entitled to an extra sense of satisfaction when they successfully grow and propagate their orchid species.
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