The dendrobium tribe includes only four genera, three of which
are not widely grown. The fourth, Dendrobium, more than
compensates with its enormous number of species; estimates range from
900 to 1,400 or even more. Natives grow from India, China, and
Japan through Indonesia to Australia, New Zealand, and the islands of the Pacific.
These orchids are highly variable in size and appearance; the
largest are 10 feet or more in height, whereas the smallest require a
magnifying glass to detect the flowers. The flower colors include white,
cream, yellow, orange, pink, red, lavender, purple, and blue-plus
almost any conceivable combination of these. Dendrobium habitats
include mountainous monsoon-region forests, tropical highlands, steaming jungles, and
pine forests. Practically all dendrobium
orchids are epiphytes, though a few are lithophytic,
living in pockets of moss and leaf mold on rocks and cliffs.
Although some species possess fat pseudo bulbs, most have thin, erect or pendent
stems called canes. These emerge from a rhizome, but are usually tightly clumped
together. Inflorescences bearing from 1 to 100 or more flowers arise from the upper
portions of the cane. Plants thrive in small pots, so need infrequent
Their basic requirements are plenty of light and free air circulation. If you grow
them in the house, give them an east window or a west or south window covered with
thin curtains. Keep the humidity
up with misting or by positioning plants above trays of wet gravel.
Given their wide natural range and highly varied structure, it follows that not all
dendrobiums will thrive under the same conditions. The species mentioned here
fall into one of two classes. The first, the cool-growing species, are generally
deciduous. Water and feed these during growth; then allow the orchids a decided winter rest, with either
no water or just enough to keep the canes from shriveling. During their rest, they
appreciate cool nights of about 40° to 50°F (4° to 10°C).
The warm-growing species are generally evergreen and require water
throughout the year, though they will need somewhat
less in winter.
The genus has been classified into a number of
different sections. Space does not permit a discussion
of other than the seven sections below, but the
majority of the species of horticultural importance are
included in these. As could be expected the cultural
requirements of this diverse group vary somewhat. If in
doubt, the best approach is to treat them in all respects
as if they were cattleyas but with a little higher light
intensity. Dropping of leaves in the winter suggests
those particular plants should be kept quite dry during this season.
A small section of Asian species with deep green
leaves of good substance confined to the upper
portion of swollen canes. These can be grown in the
same way as cattleyas, including minimum
temperatures of 50°F (10°C), but require less water in winter.
A few hybrids have been made, but species are more
common in collections. The examples below are all
- Dendrobium densiflorum
- A 12 in (30 cm) four-angled pseudo bulb plant with a stem carrying many
yellow 2 in (5 cm) flowers with fringed lips.
Spectacular in flower, but the blooms are not particularly long-lasting.
- Dendrobium palpebrae
- A similar plant to the one above but the flowers are white with some orange in
- Dendrobium trigonopus
- Waxy, 2 in (5 cm) yellow flowers with a green base to the lip. The glistening
flowers are spectacular and immediately attract attention.
Orchids from this section grow naturally on the
coast on the wetter side of the great dividing range
in eastern Australia. They are epiphytes or
lithophytes with leaves of good substance on the top
of pseudo bulbs that are relatively slender and wider
at the bottom. An enormous amount of hybridizing
has been done with this section in Australia and
many attractive hybrids of great horticultural merit
are now being seen both within this section and
incorporating other sections. The three species below
are commonly cultivated and line breeding within
each of these has given us some flowers of superior
form and color. Grow in bark-based media.
- Dendrobium falcorostrum
- This one is definitely a
cool-growing orchid, appearing naturally as an
epiphyte in the great dividing range in eastern
Australia at elevations above 3300 ft (1000 m) in
cool, moist, cloud forest. This area often experiences
light dustings of snow in winter. The near-terminal
racemes bear many fragrant, pristine white flowers
about 1 1/2 in (4 cm) across in spring. This orchid will grow in
the same potting medium as the others in this
section. The orchid is reported to do particularly well on a
slab of tree fern. As a cool-grower it dislikes high
daytime temperatures. However, it still needs high
light -even full sun - in winter. D. falcorostrum is
one of the most beautiful species in this section.
- Dendrobium kingianum
- A common, easily-grown orchid, mainly lithophytic in nature. The size of the
plant can vary from 2 in (5 cm) to as much as 20 in
(50 cm) high but is commonly about 8 in (20 cm),
with the inflorescence of six or so flowers arising
from a bud at or near the top of the pseudo bulb. The
flowers are up to 1 1/2 in (4 cm) across. Flower color can be
from white through pink to deep mauve. They prefer
an altitude of about 1000 ft (300 m) in nature but
have been found growing up to 4000 ft (1200 m).
These orchids like good light and can be grown
in the same medium as for cattleyas. In hot summer
months they should not quite dry out between
waterings but must be kept drier over fall and winter
months to encourage flowering in spring.
They may make aerial growths or keikis (a
Hawaiian name for babies) that will produce roots
and these can be removed and potted or left on the
plant to flower. D. kingianum will tolerate
temperatures down to almost freezing without coming to
any harm. It is one of the few orchids that often
succeeds in the hands of someone who otherwise
knows nothing about the cultivation of this plant family.
- Dendrobium speciosum
- By far the largest plant in this section. Two to six leathery leaves and long
racemes with up to 80 densely packed; 2 in (5 cm),
or larger, white to yellow flowers. A large plant
in flower is spectacular. This is a variable species
that is found in Australia from northern Queensland
down to Victoria, a distance of some 3000 miles
(5000 km) north to south. Southern forms are quite
cool-growers and should be grown much the same as
D. kingianum. However, the species does like plenty
of light, and it can be left outside in full sun where
it will tolerate light frosts but needs shelter from
wind and rain to preserve the flowers.
- Dendrobium tetragonum
- A rather variable species with a wide latitude range. The pseudo bulbs are thin
at the base and thicker and four-angled at the top,
where the weight often results in pendulous growths.
The length of these is as variable as D. kingianum.
Two to four greenish or yellowish, spidery, 5 in (12 cm) flowers are borne on
short stems. Flowers in spring. Some northern forms can flower at any time, but
these like higher minimum temperatures. This orchid is an epiphyte. Intervals between waterings
should be increased in winter even to the point of a
slight shriveling of the pseudo bulbs.
Orchids in this section are sometimes referred to as
soft cane dendrobiums, although the term is a little
misleading. The plants mentioned below are all
epiphytes, and they will survive winter night
temperatures down to 37°F (3°C) if kept dry.
- Dendrobium nobile
- The species grows naturally
from the Himalayas down as far as Vietnam at
elevations up to 4000 ft (1200 m). Finger-thick
canes, up to 20 in (50 cm) high, tend to drop their
leaves when mature and in spring bear flowers as
large as 3 in (8 cm) across, in clusters of up to three,
from the upper nodes. Temperatures near freezing
are not a problem in cultivation, nor is warm or even
hot summer weather. Flowers are in shades of pink to
purple and there is a white form (var virginalis). These orchids
can be potted using the same medium as for
cattleyas. Longer canes tend to be pendulous and
are usually staked upright to give the best flower display.
There are quite strict rules to observe if this species
is to produce flowers in spring. During summer, water
frequently and ensure that they do not lack nutrients.
During this time about 3000 foot-candles of light is
adequate. From early fall, decrease the
watering frequency and cease giving them any
nitrogenous fertilizer - but continue to feed them with phosphorus and
potassium. At this time the orchids require much more light, even full sunlight.
From the onset of winter, cease giving any nutrients
and water only to arrest any shriveling of the canes.
Normal watering and nutrition can be resumed
when flower buds appear. Failure to observe the rules
will result in long canes that produce aerial growths
or keikis instead of flowers. These can be removed
and potted when they develop roots.
- Nobile hybrids
- Over 100 years of hybridization,
occasionally incorporating other species, has given
us tetraploid plants with thicker, shorter canes and
larger, more shapely, long-lasting flowers. These
modern plants have blooms of considerable beauty
and are now often referred to as Yamamoto hybrids.
Mr. Yamamoto, in Japan, has done more to bring
them to perfection than any other of his predecessors
of earlier times.
These hybrids should be grown in the same way
as Dendrobium nobile species.
- Dendrobium aphyllum
- A widespread, showy,
Southeast Asian species with long, pendulous canes.
The mature canes drop their leaves in winter and
produce 2 in (5 cm) white to mauve flowers along
the length of the cane in spring. This species can be
grown the same way as nobile dendrobiums but does
appreciate slightly higher minimum winter
temperatures (50°F/10°C). D. pierardii is a very
similar, perhaps the same, species.
- Dendrobium fimbriatum
- A cool- to warm-growing species found in Southeast Asia. Many 2 in (5 cm)
flowers are borne on long, leafless canes in spring.
The flowers are golden yellow with a pretty fringed
lip. Treat much like nobile dendrobiums, but some
water is needed during the winter months.
- Dendrobium heterocarpum (aureum)
- A wide-spread and variable species. Most varieties in
cultivation are cool-growing and should be given
Dendrobium nobile treatment in the winter, when
they drop their leaves before flowering from leafless
canes in early spring. The flowers are 2 in (5 cm)
across and are pale yellow. This species appears in
the early ancestry of yellow nobile-type hybrids.
This Asian section has deep green leaves and stout
canes, which are covered with black or brown hairs.
They can be grown with the same light levels and
potting media as cattleyas. A humid atmosphere is
desirable. Temperature requirements vary with the
species. Flowers in this section come in winter and
spring and have white petals and sepals and,
although they appear somewhat papery, they are
quite long-lasting.. Hybrids within the section have
been made but the species mentioned below are all
attractive plants and are quite common in
collections. These are evergreen dendrobiums - they
do not drop their leaves in winter and do not have
to be kept dry during this season.
- Dendrobium bellatulum
- This is a dwarfish member
of the section with canes about 4 in (10 cm) high.
The flowers are up to 1 1/2 in (4 cm) wide with a
colorful red-orange lip. Fairly cool-growing with
minimum winter temperatures of 50°F (10°C). A
similar but even smaller species is D. margaritaceum.
- Dendrobium formosum
- This one is related to D. infundibilum but, although it has been found
growing at high elevations, plants in cultivation
seem to need warmer minimum night temperatures
(54°F/12°C) for best results. Canes are up to 18 in
(45 cm) long and bear starry white flowers larger
than those of the other two species described here.
- Dendrobium infundibilum
- Originally found at quite high elevations, this species is a cool-grower
with canes typically about 16 in (40 cm) high and
3 in (8 cm) or larger flowers borne towards the apex
of matured growths. Quite common in cultivation.
D. jamesianum is a similar, or perhaps the same, species.
Orchids in this section are small plants native to
Irian Jaya and Papua New Guinea or outlying islands
with a few extending to the Pacific. Some species
have been brought into cultivation only fairly
recently. They are high-altitude plants that rarely
survive if brought down to sea level within the
tropical latitudes where they are found. They are not
difficult to cultivate in temperate climates where
they are still definitely cool-growers, withstanding
temperatures down to near freezing but disliking
intense dry summer heat. In summer, frequent
misting and good air movement will help, but shade
them more if necessary to keep leaf temperatures
down. Some species in this section occasionally grow
in full sunshine in nature but be cautious about
subjecting the plants to this in cultivation.
There are about 28 species in the section. They
tend to have "upside down" flowers, with the lip
uppermost. Those mentioned below may all be
grown under similar conditions. As to potting
media, almost everything including sphagnum moss
has been tried. In nature the plants alternately
become wet and dry daily so a quick-drying medium
is important. The safest is probably a bark-based mix
as for cattleyas, but do not let any of them remain
dry at the roots for more than a day at the most. Firm
rules for the successful cultivation of oxyglossums have not yet been agreed
upon so do not be afraid to experiment.
- Dendrobium cuthbertsonii
- D. sophronites was the
name originally given to this species by the botanist
Schlecter because it reminded him of the unrelated
Sophronitis coccinea from Brazil. This is the gem in
the crown of the genus with flowers that last in
perfection for six months or even longer.
The plants are small, about 2 in (5 cm) high,
with leaves of heavy substance on top of small
pseudo bulbs. The flowers give the appearance of
being almost larger than the plants, up to 1 in
(3 cm) across and a 2 in (5 cm) pot can have a dozen
flowers. The common color is scarlet or orange, but
there are yellow and pink or magenta forms and
bicolors with a combination of two distinct colors.
Not found in other orchids are the dense prominent
warts on the upper surface of the leaves, the purpose
of which is not clear.
Dendrobium cuthbertsonii grows in Irian Jaya and Papua New Guinea at altitudes
of up to 10,000 ft (3000 m). This orchid is an epiphyte, on moss-covered trees
in quite heavy shade and even as a kind of terrestrial in the open on
high-altitude grassland. This suggests the orchid
may be able to adapt to a wide range of conditions in
cultivation. Particularly fine plants have been grown
on tree-fern slabs. Plants raised from seed tend to be
easier to grow than those removed from their native
habitat. The two-spotted mite likes this species and
can literally destroy plants. It is impossible to spray
under the leaves. Invert the pot and dip the foliage
in a miticide.
- Dendrobium laevifolium
- A compact, 4 in (10 cm) high orchid with usually two leaves atop flask-shaped
pseudo bulbs. The flowers arise from leafless older
bulbs at any time of the year but particularly in fall
in cultivation. Most of the plants in cultivation are
from Rossel Island, east of Papua New Guinea, and
the flowers are deep rose or mauve in color -about
the same size as D. cuthbertsonii or a little larger.
Plants with lighter colors, or even white flowers,
have been reported from Bougainville, the Solomon
Islands, Vanuatu and elsewhere. This is a pretty
species, somewhat less demanding in cultivation
than D. cuthbertsonii.
- Dendrobium prasinum
- This species deserves to be
grown more widely. It is similar to D. laevifolium but
the deep green leaves have more substance and the
flowers are white. It grows naturally in the islands of Fiji.
- Dendrobium sulphureum
- A variable species. The plant is about 4 in (10 cm) high, with several leaves
on the upper half of thin, cylindrical, clustered
pseudo bulbs bearing one or two flowers up to 1 in
(2.5 cm) long. The flowers are yellow or
yellow-green with a striking, contrasting, orange lip. This is
a pretty species and can be grown the same way as other oxyglossums.
- Dendrobium vexillarius
- This is the most abundant of all the Irian Jaya species in this section and is
found as an epiphyte in a wide range of habitats (up
to over 10,000 ft or 3000 m), in color forms from
blue to dark crimson. A somewhat taller plant than
the others mentioned here, D. vexillarius has slender
pseudo bulbs, swollen at the base, with two or three leaves on top.
The flowers, up to 1 1/2 in (4 cm) wide, are borne in clusters of several
flowers, more than one flower stem often coming from the same node at the top of
the bulb. Some growers find this species easy to grow but others say it is
difficult. The reason for this is not clear, but it is a worthwhile plant to
have. Try giving this orchid the same conditions as other oxyglossums.
There are only a few species in this section but two
are very important -Dendrobium phalaenopsis and
D. biggibum. Both are often regarded as the same
species. They are found in the north of eastern
Australia and in Papua New Guinea and Indonesia.
The canes are typically about 12 in (30 cm) high,
but can be much higher. They are cylindrical and
slightly swollen in the middle, with a few leathery
leaves at the top. The flower stem has many 2 in
(5 cm) or larger, long-lasting flowers in white or
shades of pink through to intense, deep purple.
D. biggibum, the Cooktown orchid, is the state
flower of the state of Queensland, Australia. The
shape of the flowers is reminiscent of the quite
unrelated genus Phalaenopsis, the moth orchid.
These plants come from areas with hot, wet
summers and somewhat drier winters and this
indicates their requirements in cultivation. They
must be dried quickly between watering in all
seasons, and need a quick - draining potting medium.
Keep them in as small a pot as possible. The plants
can stand quite high light intensities. Grown
indoors, they will survive with minimum night
temperatures of 50°F (10°C), but for best growth
and flower quality in the fall they really need
minimums of nearer 60°F (15°C) all year. These are
The plants in cultivation labelled Dendrobium
phalaenopsis will probably have been the product of
line breeding over several generations with flowers
of impressive size, conformation and color. Much
hybridizing with other sections has been done,
particularly with section Spatulata. All these orchids
are easy to cultivate in the tropics and are shipped around the world from Southeast Asia in a
multimillion dollar cut-flower industry. If living in a warm
temperate climate, try growing D. biggibum
'compactum', a smaller, free-flowering plant from
Queensland. Many succeed with it outdoors in
subtropical climates such as Florida.
These used to be known as ceratobiums. A feature
is the twisted sepals, which often go straight up,
giving the section the popular name of "antelope
orchids". The flowers are usually long-lasting. Most
of the species come from low elevations or sea level
and are definitely warm growers, needing a
minimum night temperature of 60°C (15°C). Plenty
of light and a warm humid atmosphere are
beneficial. A medium as for cattleyas is suitable, but keep
them growing throughout the year in small pots with
frequent wet and dry cycles. Tall canes are typical,
with leaves confined to the upper half. Flower
stems carrying several flowers arise from the nodes of
upper leaves. A few representative species are listed below.
- Dendrobium canaliculatum
- Found in Australia and Papua New Guinea growing on melaleuca trees.
Flower stems carry 50 or more 1 in (2.5 cm) fragrant
flowers in winter and spring. The flowers have white
and yellow petals and sepals with a purple lip. Keep
drier in winter than others in this section. It is a
smaller plant than other spatulatas and has been
much used in hybridization.
- Dendrobium gouldii
- A common species found growing over a wide geographic area. Flowers are
2 1/4 in (6 cm) across in white or pale violet with
rarer golden yellow forms. Also widely used in hybridization.
- Dendrobium stratiotes
- This is a majestic species with 39 in (1 m) high canes and large, long-lasting
flowers with white petals, yellow sepals and a violet
lip. Flowers throughout the year.
- Dendrobium tangerinum
- The 3 in (7.5 cm) flowers have bright orange petals and yellow sepals and
lip. This colorful plant was grown for many years under the name 'Tangerine'.
This orchid has been the parent of many hybrids.