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ORCHID SPECIES CULTURE Charles and Margaret Baker Masdevallia datura Luer and Vásquez AKA: N/A. ORIGIN/HABITAT: Bolivia . Plants were found near Inquisivi, which is between La Paz and Cochabamba. They were originally found in cloudforest at 8200 ft. (2500 m). Later writings indicate they grow at 7850-9200 ft. (2400-2800 m). CLIMATE: Station #85223, Cochabamba, Bolivia, Lat. 17.4S, Long. 66.2W, at 8367 ft. (2550 m). The record high temperature is 95F (35C), and the record low is 20F (-7C). N/HEMISPHERE JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC F AVG MAX 74 75 78 79 78 77 75 74 76 77 76 74 F AVG MIN 35 39 46 50 52 53 54 53 51 46 39 34 DIURNAL RANGE 39 36 32 29 26 24 21 21 25 31 37 40 RAIN/INCHES 0.1 0.3 0.2 0.8 1.5 2.8 3.7 2.7 1.5 0.5 0.1 0.1 HUMIDITY/% 45 44 43 44 49 59 63 67 63 57 52 49 BLOOM SEASON * DAYS CLR @ 8AM 21 19 16 12 9 5 4 2 6 12 17 18 DAYS CLR @ 2PM 20 18 12 8 6 6 4 2 6 13 16 17 RAIN/MM 3 8 5 20 38 71 94 69 38 13 3 3 C AVG MAX 23.3 23.9 25.6 26.1 25.6 25.0 23.9 23.3 24.4 25.0 24.4 23.3 C AVG MIN 1.7 3.9 7.8 10.0 11.1 11.7 12.2 11.7 10.6 7.8 3.9 1.1 DIURNAL RANGE 21.6 20.0 17.8 16.1 14.5 13.3 11.7 11.6 13.8 17.2 20.5 22.2 S/HEMISPHERE JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN Cultural Recommendations: LIGHT: 800-1500 fc. Light should be filtered or diffused, and plants should never be exposed to direct sun. Strong air movement should be provided at all times. When evaporative coolers are used, plants thrive when placed in the strong, cool, moist airflow near the outlet. TEMPERATURES: Summer days average 74-77F (23-25C), and nights average 53-54F (12C), with a diurnal range of 21-24F (12-13C). HUMIDITY: 60-65% in summer are early autumn, dropping to 45-50% for most of the year at the weather station. Averages in the cloudforest habitat are probably much greater than indicated, however. WATER: Rainfall is light to moderatre during most of the year. More moisture is probably available in the cloudforest habitat than is indicated in the climate table, however. Cultivated plants should be kept moist with only slight drying allowed between waterings. Water may be gradually reduced in late autumn, however. FERTILIZER: A balanced fertilizer mixed at 1/4-1/2 recommended strength should be applied every 3-4 weeks if plants are grown in sphagnum moss, tree-fern fiber, or osmunda. If grown in fir bark, the applications should be made every 1-2 weeks. Many growers prefer to switch from the normal balanced formula and make an application of high nitrogen fertilizer early in the year when plants are actively growing. They may then make an application of a high phosphate or "bloom booster" formula in late summer or autumn in order to promote flowering. REST PERIOD: Winter days average 74-75F (23-24C), and nights average 34-39F (1-4C), with a diurnal range of 36-40F (20-22C). Water should be reduced for cultivated plants in winer, especially those grown in the dark, short-day conditions common in temperate latitudes. Plants may be allowed to dry out somewhat between waterings, but they should never remain dry for long periods. Fertilizer should be reduced until water is increased in spring. GROWING MEDIA: Plants may be mounted on tree-fern or cork slabs if humidity is high and plants are watered at least once daily in summer. Several waterings a day may be necessary for mounted plants during very hot, dry periods. Because most growers find it difficult to keep mounted plants moist enough, they are usually grown in pots using an open, fast draining medium which contains materials that retain some moisture such as chopped sphagnum and perlite. Charcoal is often added to help keep the medium open and prevent it from becoming sour. Most growers recommend that plants be repotted every year. Repotting is usually done in late winter or early spring, but it may be done anytime between autumn and spring that does not interfere with flowering. MISCELLANEOUS NOTES: The bloom season shown in the climate table is based on cultivation records. Plant and Flower Information: PLANT SIZE AND TYPE: A 5-8 in. (13-20 cm) sympodial epiphyte. PSEUDOBULB: The secondary stems are 0.8-1.8 in. (2.0-4.5 cm) long. They are erect and enclosed by 2 loose, ribbed, tubular sheaths. LEAVES: 4.3-6.3 in. (11-16 cm) long including the 1.2-2.0 in. (3-5 cm) petiole. The erect leaves have leathery, narrowly elliptical to linea-elliptical blades that are 0.4-0.6 in.(1.0-1.5 cm) wide. INFLORESCENCE: 2.4-3.5 in. (6-9 cm) long. The peduncle emerges near the base of the secondary stem. The floral bract is 0.5 in. (1.2 cm) long, which is almost as long as the 0.5-0.6 in. (1.2-1.5 cm) flower stalk. FLOWERS: One per inflorescence. The large, showy, snow-white blossoms are said to remind viewers of a species of Datura. The sepals are white but are lightly suffused with yellow. Also, they are veined in light yellow toward the base, with a small brown spot on either side. The dorsal sepal is 1.5 in. (3.7 cm) long, 0.5 in. (1.3 cm) wide, and connected to the lateral sepals for 1.3 in. (3.4 cm), which is most of its length, to form a long, horizontal, trumpet-shaped tube. The triangular free portion at the tip contracts into a slender, erect, yellow tail that is 2.2-2.6 in. (5.5-6.5 cm) long. The lateral sepals are 1.9 in. (4.7 cm) long, 1.4 in. (3.5 cm) wide, and are connected to each other for 1.7 in. (4.3 cm). Their tips contract into slender tails that are 1.7-2.2 in. (4.3-5.5 cm) long. The petals, lip and column are also white. HYBRIDIZING NOTES: N/A. REFERENCES: Masd0, IKs18, [Phytologia 54(5):380 (1983)]. PHOTOS/DRAWINGS: . Copyright 1997, Charles O. Baker and Margaret L. Baker Sheet version 546550 ......................................................................... Please remember that this sheet is for your use only, and though it was provided free of charge, it may not be reproduced or retransmitted in any way without permission. ......................................................................... __________________________________________________________________________ "Orchid Species Culture" Charles & Margaret Baker, Portland, Oregon USA Orchid Culture & Pollination site http://www.orchidculture.com email <email@example.com> __________________________________________________________________________ "Orchid Species Culture Vol. 1 - Pescatorea, Phaius, Phalaenopsis, Pholidota, Phragmipedium, Pleione" 250 pages of culture information. "Orchid Species Culture Vol. 2 - Dendrobium" 850 pages of culture information for more than 1230 Dendrobium species. "The genus Paphiopedilum--Natural History and Cultivation" - Part 1 Dr. Guido Braem, Charles and Margaret Baker ISBN 0-9665337-0-4 Full page color photograph of each species. "The genus Paphiopedilum--Natural History and Cultivation" - Part 2 Dr. Guido Braem, Charles and Margaret Baker ISBN 0-9665337-1-2 Full page color photograph of each species. "Orchid Species Culture Vol. 3 - The Laelia/Cattleya Alliance" coming in a few months. __________________________________________________________________________