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ORCHID SPECIES CULTURE Charles and Margaret Baker Aerangis punctata J. Stewart AKA: N/A. ORIGIN/HABITAT: Madagascar. This recently described epiphytic orchid (1986) is found in center of the island at about 4600 ft. (1400 m). CLIMATE: Station #67109, Arivonimano, Malagasy (Madagascar), Lat. 19.0S, Long. 47.2E, at 4757 ft. (1450 m). Temperatures are calculated for an elevation of 4600 ft. (1400 m), resulting in probable extremes of 91F (33C) and 31F (-1C). N/HEMISPHERE JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC F AVG MAX 69 72 75 79 80 80 80 79 78 78 74 71 F AVG MIN 47 47 49 53 57 59 60 59 60 56 52 48 DIURNAL RANGE 22 25 26 26 23 21 20 20 18 22 22 23 RAIN/INCHES 0.2 0.5 0.2 2.5 5.1 8.3 12.8 8.2 8.6 1.4 0.7 0.4 HUMIDITY/% 68 67 62 64 68 70 73 75 73 73 73 69 BLOOM SEASON * DAYS CLR @ 3AM 3 10 5 10 5 3 4 3 1 8 11 5 DAYS CLR @ 3PM 2 6 3 7 2 1 0 1 0 3 6 4 RAIN/MM 5 13 5 64 130 211 325 208 218 36 18 10 C AVG MAX 20.6 22.2 23.9 26.1 26.7 26.8 26.7 26.1 25.6 25.6 23.3 21.7 C AVG MIN 8.3 8.1 9.2 11.4 13.6 14.7 15.3 14.7 15.3 13.1 10.8 8.6 DIURNAL RANGE 12.3 14.1 14.7 14.7 13.1 12.1 11.4 11.4 10.3 12.5 12.5 13.1 S/HEMISPHERE JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN Cultural Recommendations: LIGHT: 1200-2000 fc. Plants need filtered or diffused light and should never be exposed to direct midday sun. Strong air movement should be provided at all times. TEMPERATURES: Summer days average 79-80F (26-27C), and nights average 59-60F (15C), with a diurnal range of 20-21F (11-12C). HUMIDITY: 70-75% in summer and autumn, dropping to 60-65% for about 3 months in late winter and early spring. WATER: Rainfall is moderate to heavy from late spring to early autumn. Averages then drop rather abruptly in midautumn at the beginning of the dry season, that lasts about 5 months until late winter or early spring. Cultivated plants should be watered heavily while actively growing, but drainage must be excellent. Water should be reduced in autumn after new growths mature. FERTILIZER: 1/4-1/2 recommended strength, applied weekly when plants are actively growing. Many growers prefer to use a balanced fertilizer throughout the year, but others prefer to use a high-nitrogen fertilizer from spring to midsummer, then switch to a high-phosphate formula in late summer and autumn. REST PERIOD: Winter days average 69-72F (21-22C), and nights average 47-48F (8-9C), with a diurnal range of 22-25F (12-14C). Rainfall in the habitat is low from autumn to early spring. Humidity remains relatively high throughout the year, however, so considerable additional moisture is available from heavy dew and late-night mist. Cultivated plants need much less water in winter, but plants should not be completely without water for long periods. Occasional early-morning mistings between infrequent light waterings should be adequate in most growing areas. Water should be increased somewhat if leaves shrivel or show signs of stress. Fertilizer should be eliminated until new growth starts and heavier watering is resumed in spring. GROWING MEDIA: Conditions around the roots should be open and well aerated and should never be stale or soggy. As with most Aerangis species, Aerangis punctata probably grows better and the pendent flower spikes are more easily displayed when plants are mounted on slabs of tree-fern or rough bark. Mounted plants need high humidity, however, and during hot, dry weather they may require several waterings a day. If leaves start to shrivel or wrinkle or show other signs of stress, a plant usually will recover and grow well if soaked in water for about 20 minutes at least 3 times a week. Many growers find it difficult to keep mounted plants moist enough, so plants often are grown in small, 3-5 in. (8-13 cm) hanging pots or baskets using a very coarse, open, fast draining medium to anchor the plant but allow roots to wander outside the container. Plants should be repotted if the medium starts to break down. Repotting done just as new roots start to grow enables the plant to become reestablished in the shortest possible time. MISCELLANEOUS NOTES: The bloom season shown in the climate table is based on the original collection report. Joyce Stewart (1986) reported that these plants grow best when conditions are cool, well-shaded, and humid with the minimum night temperature near 50F (10C). Plant and Flower Information: PLANT SIZE AND TYPE: A very small, 1-2 in. (2.5-5.0 cm) monopodial epiphyte. PSEUDOBULB/STEM: 0.4-0.8 in. (1-2 cm) long. The stems have grayish roots with a conspicuously bumpy, warty surface and bright green tips that are flattened against the substratum. LEAVES: 0.8-1.4 in. (2.0-3.5 cm) long by 0.2-0.5 in. (0.5-1.2 cm) wide. Each growth carries 2-4 elliptic, oblong, or elliptic-oblong leaves which alternate along the stem. Leaves are dull grayish green densely marked with minute silver dots. The apex of each leaf is bilobed, and the lobes end sharply on either side of the midrib with a short sinus between them. INFLORESCENCE: 1.4-2.2 in. (3.5-2.5 cm) long, including the slender pedicellate ovary. The peduncle, which is 0.4-0.8 in. (1-2 cm) long, emerges from the stem below the leaves. FLOWERS: 1, occasionally 2-3. Blossoms are up to 1.6 in. (4 cm) across. Sepals and petals may be greenish or pale brownish. The narrowly lanceolate sepals are 0.6-0.8 in. (1.4-2.0 cm) long by 0.1-0.2 in. (0.3-0.4 cm) wide at the base with sharply pointed tips. The dorsal sepal is erect, and lateral sepals are obliquely spreading. Somewhat spreading, the strap-shaped to lanceolate petals are 0.5-0.6 in. (1.2-1.6 cm) long by 0.1 in. (0.2 cm) wide at the base. The egg-shaped lip tapers gradually to a slender, sharply pointed apex. It is widest at the middle or on the upper half with a wide entrance to the spur at its base. Overall, the lip is 0.6-0.9 in. (1.6-2.2 cm) long by 0.3-0.4 in. (0.7-0.9 cm) wide near the middle. The spur, which is 4-5 in. (10-12 cm) long, is funnel-shaped where it meets the lip and then narrows abruptly, becoming very slender from there to the tip. The short and broad column is 0.1 in. (0.3 cm) long and the anther cap has a small, pointed, beaklike projection. Aerangis punctata and Aerangis curnowiana is very similar in many respects, but Aerangis punctata differs in several ways. First, the roots are wider, flatter, and always have a bumpy surface. Leaves are differently shaped at the apex, and their surface is dotted with minute silver spots which appear to have been punctured with a pin when viewed through a hand lens. It often produces 2-3 flowers on an inflorescence but Aerangis curnowiana never produces more than a single blossom. Petals of Aerangis punctata are shorter and narrower than the sepals, but those of Aerangis curnowiana are all similar. The lip of Aerangis punctata is somewhat variable in that it is sometimes widest closer to the apex, but is always wider than the lip of Aerangis curnowiana. HYBRIDIZING NOTES: N/A. REFERENCES: Stewart, J. 1986. Stars of the islands - A new look at the genus Aerangis in Madagascar and the Comoro Islands - 4. American Orchid Society Bulletin 55(11):1117-1125. PHOTOS/DRAWINGS: Stewart, J. 1986. Stars of the islands - A new look at the genus Aerangis in Madagascar and the Comoro Islands - 4. American Orchid Society Bulletin 55(11):1117-1125. (Drawing and color photo) Copyright 1999, Charles O. Baker and Margaret L. Baker Sheet version 65801903 ......................................................................... 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 <cobaker@troymeyers.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. __________________________________________________________________________