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The genus Angraecum, abbreviated as Angcm in horticultural trade,
common name Angrek (Malay and Bahasa) or Comet Orchid, contains
about 220 species, some of them among most magnificent of all
orchids. They are quite varied vegetatively and florally and are
adapted to dry tropical woodland habitat and have quite fleshy
leaves as a consequence. Most are epiphytes, but a few are
lithophytes.
Tropical Africa and Madagascar contain the majority of the genus
with one outlier found on Sri Lanka, and three species once thought
to belong to the genus in Japan and the Philippines. But these
orchids can also be found on the Comoros, the Seychelles, and the
Mascarenes. They occur between sea level and 2,000m in humid
regions.
The long-lasting flowers are racemose and grow from the leaf
axils. They are mostly white, but a few are yellow, green or ochre.
They all have a long spur at the back of the labellum (lip).
In the case of Angraecum sesquipedale, a species from Madagascar,
on observing the 30cm spur in the lip, Charles Darwin made the
hypothesis that, since the nectar was at the bottom of the spur, a
pollinator must exist with a tongue at least that long. Otherwise
the orchid could never be pollinated. At the time, he was not
believed. However, in 1903, the predicted pollinator was discovered,
a hawk moth then named Xanthopan morganii praedicta ("praedicta"
meaning "the predicted one"). It has an appropriately long
proboscis. The specific name sesquipedale means "one foot and a
half", referring to the length of the spur. This is a perfect
example of mutual dependence of an orchid and a specific pollinator.
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[edit] Angraecum Conservation
Many species of Angraecum orchid are considered to be at risk of
extinction in the wild and are protected from international trade
under CITES. The genus Angraecum is listed as one of the top
conservation priorities by the International Union for Conservation
of Nature and Natural Resources (IUCN) Orchid Specialist Group. Many
of the species, such as Angraecum sororium, are endemic to
Madagascar and are threatened from over collecting, loss of hawkmoth
pollinators, habitat fragmentation, and fire.
[edit] Growing Angraecums
Much like all other orchids, Angraecums have no need for special
care or attention. Like all other orchids it is best to water in the
mornings to avoid fungal rot due to overnight dampness. Feeding as
per other orchids and similar light conditions: in humid and hot
regions (sub tropical) feed fortnightly during growing season
(Summer) with a certified orchid fertiliser following directions on
packet, weaker solutions are also okay if you're worried. In summer
water weekly or more depending on situation. Angraecums flower best
when in a lighter position. Keep out of direct sunlight as this can
damage (and eventually kill) the plant. Most Angraecums will have
their leaves for a number of years so any sun burn spots are ugly
for a significant period and also may expose your plant to disease.
In indirect sunlight the Angraecums will reward you with blooms and
attractive growth.
Angraecum Veitchii: a very rewarding orchid. In indirect light
and watered/fed regularly this plant will produce blooms annually
(usually in Late Winter to Spring - for Australia this occurs in
August - excellent for those wanting to show their plants at
Brisbane's Ekka! You will notice a few lovely specimens there in the
Gardening Exhibits). The flowers last a while if kept in a sheltered
position and their strong heady fragrance is delightful. They only
release their perfume at night. Flowers are large (4 - 9 cm across),
waxy, white to greenish cream in colour and borne on stems of seven
to ten depending on the faithfulness of your fertilising, watering,
and indirect light provision. The leaves are large, thick straps
that alternately fan out from a central (monopodal) stem. Pups (keikis)
form at the base of the stem and can either be divided from the
parent plant once they have at least three roots of their own or
alternatively, left on the plant these will make a stunning specimen
as when mature will produce blooms with the parent plant - many
award winning angraecum veitchiis are grown as such. In the right
conditions these orchids are healthy and require little attention.
As they are epiphites the potting mixture should be loose and free
draining. Prolific roots are formed from the base and also amongst
the lower half of the foliage. These are attractive although
somewhat troublesome when moving plants to and from shows. Once your
angraecum is big it is best to pot it in a heavy terracotta pot or
place a brick in the bottom of the pot in order to ensure your
beauty does not get top heavy and risk snapping when blown over in
the wind (especially since they flower during the windier times of
the year, this can be very sad). When watering a good soaking with a
hose or watering-can is best (not just a misting from a spray gun)
as this helps to flush away any salts from fertilisers that may be
present in the potting mixture and also thoroughly wets the plant.
Make sure the roots halfway up the stem get a soaking too, not just
the potted roots. This is a great orchid and will give you years of
pleasure. They're slow growing and require little attention. Very
hard to kill. |
