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ORCHID SPECIES CULTURE Charles and Margaret Baker Bifrenaria harrisoniae (Hooker) Rchb. f. AKA: Dendrobium harrisoniae Hooker, Maxillaria harrisoniae (Hooker) Lindley, Lycaste harrisoniae (Hooker) B. S. Williams, Colax harrisoniae Lindley, Maxillaria pubigera Kraenzlin, Maxillaria spathacea Lindley, Stanhopea harrisoniae G. Don. ORIGIN/HABITAT: Brazil near Rio De Janeiro. Plants grow on almost vertical, east facing rock cliffs at 700-2600 ft. (200-800 m). The plants grow exposed to strong winds and almost full sun with their roots buried in cracks in the rock face that contain detritus but little in the way of vegetable matter. CLIMATE: Station # 83743, Rio De Janeiro, Brazil, Lat. 22.9S, Long. 43.2W, at an elevation of 89 ft. (27 m). Temperatures are adjusted to a habitat elevation of 1640 ft. (500 m) resulting in probable extremes of 96.8F (36.0C) and 40.8F (4.9C). N/HEMISPHERE JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC F AVG MAX 70 71 70 72 74 77 79 80 78 75 72 71 F AVG MIN 58 59 60 61 63 66 68 68 67 64 61 59 DIURNAL RANGE 12 12 10 11 11 11 11 12 11 11 11 12 RAIN/INCHES 1.6 1.7 2.6 3.1 4.1 5.4 4.9 4.8 5.1 4.2 3.1 2.1 HUMIDITY/% 77 75 78 78 78 78 74 78 81 80 79 78 BLOOM SEASON * ** *** *** * * * DAYS CLR @ 9AM 9 10 6 7 4 4 6 5 8 5 6 8 RAIN/MM 41 43 66 79 104 137 124 122 130 107 79 53 C AVG MAX 21.0 21.6 21.0 22.2 23.3 24.9 26.0 26.6 25.5 23.8 22.2 21.6 C AVG MIN 14.4 14.9 15.5 16.0 17.2 18.8 19.9 19.9 19.4 17.7 16.0 14.9 DIURNAL RANGE 6.7 6.7 5.6 6.1 6.1 6.1 6.1 6.7 6.1 6.1 6.1 6.7 S/HEMISPHERE JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN Cultural Recommendations: The following recommendations are based on averages in the habitat which should be approximated in cultivation. Reports from growers are included when they report success with conditions in cultivation that are outside the range indicated in the habitat. LIGHT: 3000-4500 fc. Since B. harrisoniae is normally found growing in exposed locations on east facing cliffs, full morning sun with afternoon shading is indicated. TEMPERATURE: Summer days average 77-80F (25-27C), while nights average 66-68F (19-20C), producing a diurnal range of 10-12F (6-7C). HUMIDITY: 75-80% throughout the year. WATER: Moderate water is required during the growing season. Care should be taken to keep water off the leaves of new growths. FERTILIZER: A balanced fertilizer mixed at 1/4-1/2 recommended strength should be applied once a week during periods of active growth. After new growth is mature, use a fertilizer with less nitrogen and more phosphorus to allow the new growth to harden before winter and to promote better blooming the following season. To prevent salt buildup during periods of heavier fertilizer applications, the pot should be leached or flushed every month or so. This is accomplished by prewetting the media and then flushing with water equal to twice the volume of the pot. REST PERIOD: Winter days average 70-72F (21-22C), while nights average 58-60F (14-16C), producing a diurnal range of 10-12F (6-7C). Along with the cooler temperatures, water should be reduced to occasional misting or light watering and fertilizer eliminated for about 2 months in winter. Gradually resume normal water and fertilizer applications when new growth starts. Successful growers report that these plants should not be treated too well in winter. They suggest that water and fertilizer applications be restricted to every second or third time that Cattleyas are watered and fed. The pseudobulbs should shrink and even shrivel a bit during the winter rest. In addition, growers indicate that plants should be placed high in the greenhouse to receive maximum light. GROWING MEDIA: B. harrisoniae grows well mounted on slabs or rafts if high humidity can be maintained and sufficient water can be provided. Medium sized fir bark produces good results for most growers who use pots. Successful growers suggest that these plants grow well in a potting mix more like one used for Paphiopedilum than one used with Cattleya. They further indicate that fir bark with a little coarse sphagnum and some perlite added produce excellent results. MISCELLANEOUS NOTES: Because these plants are intolerant of being disturbed once established, repotting should be done only when necessary and then only when new root growth is starting. When dividing, each division should consist of 4-5 pseudobulbs. Growers report that they have never found what initiates blooming, and that some plants never bloom. Whether or not they were providing the conditions indicated above is not known. Plant and Flower Information: PLANT SIZE AND TYPE: B. harrisoniae is a medium sized 10-16 in. (25-41 cm) lithophyte that is sometimes found growing as an epiphyte. PSEUDOBULBS: The clustered, ovoid pseudobulbs are 2.0-3.5 in. (5-9 cm) tall and often suffused with red-brown, especially near the apex. LEAVES: The single oblong leaf is 7-12 in. (18-31 cm) long and may be 5 in. (13 cm) wide. It is stiff and upright, leathery in texture, and glossy dark green. INFLORESCENCE: Normally 2 per growth, they emerge from the base of the newest pseudobulbs. They are usually about 2 in. (5 cm) long and bear 1-2 flowers. FLOWERS: The 2.5-3.0 in. (6-8 cm) flowers are waxy in texture, long lasting, and are heavily fragrant. The oval-oblong sepals and petals are spreading with a smaller concave dorsal sepal. Usually white, they may be yellowish or greenish yellow. The large lip is 3 lobed, hairy, rich wine-purple to magenta-red with darker veins. HYBRIDIZING NOTES: B. harrisoniae has not been used extensively in breeding, but it has been successfully crossed with other members of the subtribe Lycastinae as well as with allied genera such as Zygopetalum and Huntleya. REFERENCES: Associação Orquidofila de São Paulo. 1977. Native orchids of Brasil. Editora Gráfica Topan-Press Ltda. São Paulo, Brazil. Bechtel, H., P. Cribb, and E. Launert. 1980. Manual of cultivated orchid species. MIT Press, Cambridge, Mass. Hawkes, A. D. 1987. Encyclopaedia of cultivated orchids. Faber and Faber, London. Pabst, G. F. J. and F. Dungs. 1975. Orchidaceae Brazilienses. Brücke-Verkag Kurt Schmersow, Hildesheim, Germany. Teuscher Henry. 1972. Bifrenaria harrisoniae and B. inodora. American Orchid Society Bulletin, Vol 41, No. 11 (Nov. 1972). Veitch, James, and Sons. [1887-1894] 1963, 1981. Manual of orchidaceous plants. Vols. I-II. James Veitch and Sons, Royal Exotic Nursery, Chelsea, London. Reprint, Vol. I, A. Asher and Co., Amsterdam, The Netherlands; reprint, Vol. II, Bishen Singh Mahendra Pal Singh, Dehra Dun, India. Copyright 1997, Charles O. Baker and Margaret L. Baker Sheet version 546354 ......................................................................... 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 <firstname.lastname@example.org> __________________________________________________________________________ "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. __________________________________________________________________________