Common Names: Leon’s Angraecum [Leon Humblot – French Orchid Collector in Madagascar and the Comoros Islands 1800’s].
For many years, this genus was known only from a few plants owing to difficulties in importing them from the far-away habitats. Today, many species in this genus are grown from seed, which makes them more readily avaiable to growers, who can discover the many species available by reading books. Handsome in or out of bloom, angraecums usually have white to creamy green blooms that are borne one to many on axillary inflorescences. The flowers are often fragrant at night.
Various botanists have revised the genus Angraecum and tried to divide it into sections. In 1973, the American botanist Leslie Garay has proposed to divide the genus Angraecum into 19 sections. His work is still a reference: 7 sections are strictly endemic to Madagascar and the Indian Ocean Islands. 10 sections are common to Madagascar and Continental Africa. 2 sections are only found in Continental Africa His work is still a reference: 7 sections are strictly endemic to Madagascar and the Indian Ocean Islands. 10 sections are common to Madagascar and Continental Africa. 2 sections are only found in Continental Africa [Systematics of the Genus Angraecum (Orchidaceae), Kew Bulletin (1973)]
Pollination is insured by moths that have a trump that is adapted to the length of the flowers’ spur. The moths are attracted by the powerful fragrance of the flower and guided by the white color of the labellum that is well visible at night.
For more interesting facts from Angraecum biography , please, read in our article ‘Angraecum sesquipedale or Darwin’s prediction’
There are two forms of this species found in very different areas. The smaller form is found at the northern tip of Malagasy (Madagascar) growing near sea level. The second and larger form is found in the Comoro Islands growing at about 3000 ft. (910 m).
To proper understand this paragraph, please refer to Introduction to Orchid Species Culture Climate Tables Metherogical Station #67009, Diego Suarez, Malagasy, Lat. 12.3S, Long. 49.3E, at 95 ft. (29 m). Record extreme temperatures are 98F (37C) and 63F (17C).
N/HEMISPHERE JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
F AVG MAX 84 84 84 86 88 90 88 89 88 88 85 85
F AVG MIN 69 69 70 72 74 75 75 75 75 75 74 71
DIURNAL RANGE 0.2 0.2 0.2 0.4 0.9 4.9 10.4 8.1 7.2 2.3 0.3 0.3
RAIN/INCHES 3.4 4.0 6.4 8.7 8.2 17.1 12.2 7.4 8.7 5.2 3.7 3.4
HUMIDITY/% 65 65 66 69 73 76 82 83 81 76 69 67
BLOOM SEASON * * ** ** ** * * * * * * *
DAYS CLR @ 3AM 21 21 21 21 14 11 10 9 10 13 19 20
DAYS CLR @ 3PM 10 14 16 19 12 4 2 1 1 7 13 12
RAIN/MM 5 5 5 10 23 124 264 206 183 58 8 8
C AVG MAX 28.9 28.9 28.9 30.0 31.1 32.2 31.1 31.7 31.1 31.1 29.4 29.4
C AVG MIN 20.6 20.6 21.1 22.2 23.3 23.9 23.9 23.9 23.9 23.9 23.3 21.7
DIURNAL RANGE 8.3 8.3 7.8 7.8 7.8 8.3 7.2 7.8 7.2 7.2 6.1 7.7
S/HEMISPHERE JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
The following recommendations are based on averages in the habitat. They may be used as a guide for newly acquired plants whose requirements are unknown, or for plants that are not growing or flowering as well as they should. Reports from growers are included when they indicate success with conditions in cultivation that are outside the range found in the habitat.
Light 2500-4000 fc. Plants may tolerate as much as 50% sunlight if gradually introduced to the higher levels. Plants will bloom under a wide range of light levels, however, and high light is not necessary or recommended.
Temperatures Summer days average 88-90F (31-32C), and nights average 75F (24C), with a diurnal range of 13-15F (7-8C). Conditions throughout the year for the Comoro Islands form average about 10F (6C) cooler than indicated for the Madagascan form.
Humidity 75-85% from summer into autumn, decreasing to near 65% in winter and spring.
Water Rainfall is moderate to heavy from summer to early autumn. Cultivated plants should be watered sufficiently to keep the foliage plump and firm. If leaves become shriveled or wrinkled, water more often, or move the plant to an area where it is misted more frequently during the summer. The summer wet season is followed immediately by a very dry season from late autumn into spring when conditions are so dry that even dew is uncommon. The dry season for the Cormoro Island form is neither quite so long or as severe as indicated for the Madagascan form.
Fertilizer A balanced semy-hidro fertilizer, should be applied each wattering during periods of active growth. Here is the article about our view to Orchids diet.
Many growers use a fertilizer with lower nitrogen and higher phosphate in autumn. In our fertilizer recipe you may ease rich this goal by increase quantity of FloraBloom from Flora Series. To recalculate new fertilizer solution, use our Calculator PPM for hydroponic fertilizer solutions. This improves blooming the next season and encourages new growths to harden before winter. Pots should be leached every few weeks to prevent salt buildup, especially when fertilizer is being applied most heavily. Plants should first be watered normally to dissolve any accumulated salts. An hour or so later, the medium is 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 Winter days average 84-85F (29C), and nights average 69-71F (21-22C), with a diurnal range of 14-15F (8C). Rainfall is low during a 6 month period in winter. Water for cultivated plants should be greatly reduced during this time. Usually, an occasional early morning misting is sufficient if a period of bright sunny weather is expected. Water should be increased if the leaves show signs of stress by becoming wrinkled. Extreme care should be taken not to overwater potted plants, however, since the symptoms for root rot caused by too much water are the same as the signs indicating a lack of water.
Growing media Plants may be mounted on slabs of cork or tree-fern fiber, with a small pad of osmunda or sphagnum moss if high humidity must be maintained, and if water can be applied at least daily during the summer. If potted, a very open, fast draining medium such as medium to large fir bark or cork nuggets is recommended. Some growers report that plants grow well when potted in coconut fiber. Undersized pots large enough to hold the roots should be used, and repotting should be done just as new root growth is starting, or as soon after flowering as possible.
Miscellaneous notes The bloom times indicated in the table are based on cultivation reports. In nature, A. leonis blooms in late winter, near the end of the dry season.
Plant and Flower Information
Plant size and type A medium sized epiphyte that grows to 6-8 in. (15-20 cm) wide, and is usually less than 6 in. (15 cm) tall. While usually a monopod with a short, stout stem, secondary growths will occasionally be made from near the base of the stem. All measurements given are for the Madagascan form. The Comoro Island form may be as much as twice the size indicated.
Leaves Usually there 4-5 thick, sickle-shaped, distichous leaves on the almost stemless plant and any one time. They are 4-6 in. (10-15 cm) long and 0.6-1.0 in. (1.5-2.5 cm) wide.
Inflorescence 1-2 stout inflorescences emerge from below the leaves. They are 3-4 in. (8-10 cm) long, and may be erect or suberect.
Flowers 1-7 on each inflorescence. The long-lasting, fragrant flowers are pure white and measure 1.2-1.6 in. (3-4 cm) wide and 1.6-2.0 in. (4-5 cm) tall.
Hybridizing notes Chromosome count is 2n = 40.
Aeranthus leonis (H.G. Reichenbach), Angraecum humblotti Rchb. f., Mystacidium leonis Rolfe, and Macroplectrum leonis Finet
Charles O. Baker and Margaret L. Baker. Sheet version 4024645 Internet Orchid Species (Jay)