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The following article was written for the
Orchid Species Bulletin published by the Orchid Species Society,
which is based in Brisbane, Queensland in June 2009.
Bear in mind that any cultivation notes refer to the sub-tropical conditions of Southern Queensland, Australia.
Bulbophyllum
rufinum Rchb.f.
was described by Heinrich Gustav Reichenbach in
Xenia
Orchidaceae in 1881. The specific epithet comes from the Latin rufus
(dull yellowish or brownish-red) and the suffix –inus
(indicating possession or resemblance) for the colour of the flowers.
Bulb.
rufinum has oblong, 4-angled pseudobulbs that are
up to 5 cm long, and are borne along a creeping rhizome. At the apex of each pseudobulb is a single oblanceolate leathery leaf
that is up to 25 cm long, which is borne on a petiole (stalk) that is up to 10
cm long. Long stiff decurved racemes
that are 15-25 cm long, bearing 2-3 large basal sheaths are produced from the
base of the matured pseudobulb. These
carry well-spaced flowers that are about 1 cm long and are yellow to
yellow-green, marked with purple to red-brown streaks. Variable in colour the flowers may be nearly pure yellow to marked with
much purple to red-brown. In
addition the rachis varies from light green to purple. The blooms are subtended by white lanceolate bracts that are twice as
long or more, as the pedicel plus ovary.
Distributed
in Thailand, Burma (Myanmar), Laos, Vietnam and Cambodia, Bulb.
rufinum usually grows on trees in deciduous forest. The habitat usually experiences a prolonged dry
season. It is a tough species that will tolerate brighter light, particularly
during its cool rest period. To
accommodate its creeping habit Bulb.
rufinum is best grown in a shallow tray or basket with a well-drained
medium, or mounted. It can be
mounted on cork bark, hardwood or tree fern but may need daily watering or
misting during the warmer months. Grow
it under 70% shade and water it regularly while it is actively growing. Maintain high humidity with good air
circulation. During the winter and when Bulb.
rufinum is not actively growing reduce the watering frequency but do not
allow the plant to remain dry for long periods. Occasional misting or watering in the mornings of sunny days will prevent
the pseudobulbs from shrivelling. I
would recommend a winter minimum of 12 oC.
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