A Review of the "Antelope" Dendrobiums
(Section Ceratobium) — Part 5 —
Subsection Mirbeliana
DR. CLAIR RUSSELL OSSIAN
IN THE PRECEDING four parts of this series, I have reviewed the
subsection Minacea with its strange, spidery, long-horned forms and the
subsection Platypetala with its numerous, more conventional shapes.
Together, those twenty-four species already discussed have had a great
impact on the breeding history of modern hybrids, although some of
them are extraordinarily rare and seldom seen today.
With the exception of Dendrobium capra, members of the subsection
Mirbeliana are much better known, and several of its species are very
often used by today's hybridizers. The most commonly used species of this
latter group is Dendrobium gouldii, a taxon that has been used and
awarded under a variety of names. While not all readers will be happy
with the treatments I will propose for some of the more variable species, it
is generally known and accepted that several of them are quite variable.
Because of the complexity of Dendrobium gouldii and Dendrobium
mirbelianum and their impact on our hybrids, I will examine their problems
in some detail.
The definition of this subsection is straightforward: petals are linear
(straight and narrow) at their bases and spathulate (spoon-shaped)
distally. Petals are barely longer than the sepals and are sometimes
(rarely) subequal. The sepals are always rather narrow.
KEY TO SPECIES
Subsection Mirbeliana
A. Labellum with three keels.
1. Labellum with three simple keels running parallel from the base to a
point near the tip of the median lobe. Labellum median lobe
elongate, oblong, and pointed; lateral lobes elongate, midlobe
long, with undulate margins. Flowers typically olive green,
yellow-brown, or brown with a violet suffusion; labellum yellow
with a median light stripe and violet veins.
………………………………………….Dendrobium warianum
2. Labellum with three simple keels that arise at the base, running
forward and merging in mid-disc. Lateral labellum lobes broadly
semi-orbicular, median lobe ovate. Flowers either yellow-brown
with a brown overlay or yellow suffused with violet. The labellum
yellowish with violet veins and white
keels……………………………Dendrobium pseudoconanthum
B. Labellum with five keels.
1. Keels parallel from the base of the labellum to the proximal parts of
the median lobe, but only the center three keels continue on to reach
the center of the median lobe. Distal ends of the keels elevated to
form tall teeth on the disc of the labellum.
a. Lateral labellum lobes shaped like parallelograms with rounded
distal margins while median lobes oblong and pointed. Flowers
generally green-yellow with a grayish midstripe on each petal
and sepal. Labellum pale yellow with dark purple keels on the
median lobe and dark brown-purple veins on the lateral
lobes……………………………………Dendrobium capra b. Lateral labellum lobes long and rounded to triangular; median lobe
short-spathulate to ovate-cordate. Flowers variably colored,
yellow, brownish, purple, and bluish forms being most common;
labellum likewise variable with purple veins on the lateral lobes
and violet keels on the median lobe …………..Dendrobium gouldii
2. Labellum keels subparallel and tightly pressed together such that
the median one is longest and nearly reaches the tip of the
labellum; the next pair is slightly shorter, but the outermost pair
just barely reaches the disc of the labellum. Lateral labellum
lobes semi-ovate; median lobe ovate to lanceolate and heavily
undulated. Flowers light yellow-green; labellum greenish and
veined with dark violet-brown.........Dendrobium mirbelianum
Dendrobium capra J. J. Smith 1910 This simple, yet handsome flower is apparently nearly unknown in
culture today. My only source of firsthand information was not even able
to provide me with data about overall plant size, nor is there any
statement in the literature to help. There are clues suggesting that the
plant is tall at least (J. J. Smith suggested that the species was only
forty-four centimeters tall, but so many of the early reports were
prepared from extra-small plants that I am inclined to put more trust in
later sources. Faced with collecting and transporting some of these
orchid monsters, I suspect that more than one despairing collector
decided to pick the smallest plant in the patch). J. J. Smith stated that
the plants are thick at the cane bases, tapering upwards to fractiflex
(zigzagged) tips. Lower parts of the elongate canes bear only leafless
sheaths, while the upper parts are leafy. In the materials described by
J. J. Smith, there were only four to seven leaves present. Leaves are
linear-lanceolate with small, sharp points at the leaf tips (some with two
points). Flower stalks are produced from among the leaf bases, spread
laterally outward, and are laxly adorned with up to twenty flowers.
The dorsal sepal is linear-lanceolate to triangular with a small point
at the otherwise blunt tip. Lateral sepals are much the same and none of
the sepals are twisted, though there may be slight reflexing. Petals are
linear-spathulate, though only slightly expanding towards the rather
blunt tips. Petals also reflex somewhat, but, as in the sepals, there is
little twisting observed.
Labellum lateral lobes are in the shape of slightly skewed
parallelograms with rounded distal margins. The median lobe is
broadly oblong, with a long and definite point. Keel arrangement in
this species is quite distinct. As stated in the key, a median keel arises
at the base of the labellum and extends far enough forward to nearly
reach the tip of the median lobe, while the adjacent two keels are only
slightly shorter. The outermost pair of keels hardly reaches past the
anterior parts of the median lobe.
Flower colors seem to be rather stable, with the sepals and petals
being greenish-yellow with a gray stripe down the center of each of the
floral elements. The labellum is paler and more nearly yellow, bearing
prominent veins on the lateral lobes and obvious keel stripes — both
veins and keels are purple to dark brownish purple.
Natural spread is reported to be 3 cm, with the dorsal sepal 1.75 cm
long by 0.3 cm wide, lateral sepals 1.75 cm long by 0.3 cm wide, and
petals 2.25 cm long by 0.25 cm. wide. The labellum measures 2 cm
long by 0.4 cm wide.
Dendrobium capra occurs in Java and Malaya. No published records
exist for the flowering dates.
Dendrobium gouldii Reichenbach f. 1867 This and the next species, Dendrobium mirbelianum, have the worst series
of synonyms in the whole section — twelve for Dendrobium gouldii and
thirteen for Dendrobium mirbelianum. These long lists of superfluous
names immediately suggest that these species are highly variable,
and this is indeed the case. Most of the synonyms for Dendrobium
gouldii are part of the ancient history of orchid taxonomy and do not
need reviewing here. Several however are still much in current
usage by plant dealers and hybridizers. Three of the twelve
synonyms cause most of the trouble — Dendrobium veratrifolium,
Den. lineale, and Den. "Guadalcanal".
As discussed in the introduction to this series (Part 1), the
concept of a geographic cline helps us to understand the problem. A
cline contains all those variations found within a species throughout
its geographic range, and as the distance from one extreme of the
cline to another increases, the chances for breakdown into new
species also increase. If strong climatic changes are also
superimposed on a broadly distributed cline, even more pressure is
brought to bear on the members of
Grower: George
Kennedy
Photograph:
George Kennedy
Dendrobium
capra
the cline and the individual variants become more distinct until the
cline fails and fragments into new species. From the literature we see
that Dendrobium "lineale" is found in New Guinea, New Ireland,
and the northern Solomon Islands. Dendrobium "veratrifolium" is
reported from northern and northeastern New Guinea and the
adjacent, small islands. Dendrobium gouldii (in the original sense) is
found in New Guinea, New Ireland, Bougainville, the Solomon
Islands, New Hebrides, Tamara Island and northern Australia.
Throughout all these sites we see trends — Dendrobium "lineale" is
reserved for the white and mauve forms; Dendrobium "veratrifolium"
flowers are white to lavender; Dendrobium "Guadalcanal" flowers
are yellow and brown, while Dendrobium gouldii covers all the
other color variants (blues, pinks, darker purples, etc.). When the
geographic distributions of the flower shapes and the color
variations discussed above are plotted on a map, it becomes evident
that the concept of the cline helps to reunite these fragments into a
common species.
I wish to suggest that this polymorphic species may have been among
the first of the Ceratobium Dendrobium species to evolve in the area
surrounding New Guinea. During the very low sea-level conditions
discussed in Part 1 of this series, there would have been few (if any)
serious barriers to species dispersal as a jungle began to occupy areas
that had once been sea floor between scattered islands. The remnants of
this old oceanic floor as preserved today suggest that this ancestral
region would have been broad and flat — ideal for the dispersal of a
near-equatorial species which was evolving and changing rapidly. By
the time sea levels began to rise again, many of the sub-populations
were far from the ancestral source areas and were quickly isolated by
the invading ocean tongues. In order to escape this inundation these
Dendrobium gouldii,
one of the “lineale”
types, shown here
producing a massive
floral display
outdoors in New
Guinea
surviving subpopulations would have been driven from the lowlands
and forced to retreat up the mountainsides to locations that are now the
present sea shores.
Invoking the concept of the geographic cline then suggests that during
the period of low sea levels we would have found a continuous variety
of shapes and colors that would have been gradational from the more
standard types to the most extreme variants. When the sea levels rose
again, this continuous distribution fragmented into subgroups — cline
fragments. The scattered and isolated variations continued to evolve
but more slowly, now that they lacked access to the common pool of
genetic materials for their species. Each distinct subpopulation thus
became more distinct through time until we arrive at the present
situation. Isolation has long been known to be a potent force in the
production of new varieties and species, and here we see a fine
example of the process.
Grower: Margaret Ilgenfrtiz
Dendrobium veratrifolium 'Elizabeth', CBM/AOS
(80 pts), actually a form of Dendrobium gouldii.
Several papers have appeared with partial solutions to the problem.
Oakes Ames (1947) recognized the essential similarity of Dendrobium
veratrifolium and Dendrobium gouldii, and Womersley (1978) cited the
common identity of Dendrobium gouldii and Dendrobium lineale, but
the most important paper was that of Hunt (1970) where he has
summarized the problem, made lists of all the known and inferred
synonyms, and provided a capsule history of the evolution of the identity
of Dendrobium gouldii and its synonyms. Hunt visited the home ranges
of these variants, recollected them, made notes on their colors, pickled
examples of each type in preservative solutions and returned home. At
that point he made the alarming discovery that the preservative
solution had bleached the colors away, and without color hues to
separate them, all the variants were identical in their significant
Dendrobium gouldii, a color variant frequently called
Dendrobium lineale.
Grower: Amlree Millar Photography: Andrei- Millar
details. Millar (1978) has unfortunately perpetuated the problem
somewhat she prefers to use the synonymous name of Dendrobium
lineale. While it is certainly true that taxonomic decisions are in part the
opinions of their authors, works like those of Hunt (1970), and Ames
(1947) and Womersley (1978) seem to provide powerful proofs for the
need to combine these species names under the senior synonym of
Dendrobium gouldii.
The plant habit of Dendrobium gouldii is tall to very tall (120-210 cm),
with stems that are relatively thick, sparsely jointed and leafy. The
leaves are broadly linear, thick and fleshy, grooved on their upper
surfaces, and quite rigid. As in all the Ceratobium species, the flower
spikes are produced from the upper leaf axils. These spikes are long,
erect in stature and carry twenty-five to thirty flowers on the most
Grower: C.R. Ossian Photography: C.R. Ossian
ABOVE AND RIGHT,
Dendrobium gouldii, a “lineale” type
from the Moroki Islands, flower and
detail of labellum keels.
robust specimens. Strong plants may produce multiple spikes from
each cane, as shown in the accompanying illustrations.
The dorsal sepal is somewhat variable in shape (as are all the flower
parts, depending on where the plants were collected), but it is mainly
linear-ligulate and is generally recurved to some degree. Lateral sepals
are somewhat to very falcate, ligulate and recurved. Great variation is
seen in the petals from forms like those in the line drawing: blunt forms
like the "lineale" variant (see photograph), and elongate elegantly
twisted shapes like those seen in the other photograph ("blue" type).
In all the variants, the petals are elongate, expanded at the tips, erect
and twisted to a greater or lesser degree.
Lateral, labellum lobes are erect, rounded to triangular, and
elongate. The median labellum lobe varies from somewhat spathulate
shapes to those that are ovate or cordate. Labellum keels are somewhat
like those of Dendrobium capra in that the middle one is the longest and
the outer, most lateral pair is the shortest. Here, however, all of the
keels fail to more than just reach the proximal parts of the median lobe.
At their distal ends, each of the middle three keels is elevated into a very
large and obvious blade-like shape. This feature allows one to easily
distinguish Dendrobium gouldii from all of the other Mirbeliana
species.
The color variations were discussed above and are highly variable
indeed. The labellum in each color variant is tinted a complementary
hue, and all types have a pattern of lines over the lateral labellum lobes
and a series of color stripes down the crests of the keels. These lines
and stripes are commonly reddish, lavender or brownish. The
commonest types usually have purple veins on the lateral lobes and
violet keels.
Dendrobium gouldii, a form close to the type known as Dendrobium "Guadalcanal".
Grower: C. R. Ossian
Photograph: C. R.
Ossian
Grower: Leon Fowler;
Dendrobium gouldii ‘Blue’
Two horticultural varieties and one rather confused form have been
reported in the literature. The first of these is Dendrobium gouldii var. acutum
Reichenbach f. 1867. This form differs from the type only in the possession
of ovate, lateral labellum lobes, a median labellum lobe that is ovate to
subrhombic, and flowers that are said to have a thinner, overall substance. I
suspect that had Reichenbach been able to see as many materials as the later
workers have handled, he might not have named this form but would have
included it within the larger definition of the parent species.
Dendrobium gouldii 'Blue', or 'Blue Gouldii' as it is sometimes called, is
merely a variation of the species where the flowers have a definite blue
sheen when viewed in bright light. This is a highly valued form for
breeding and has been part of the source for many of the "blue" hybrids
of today's market. An illustration of this form is included here.
The last variant worth discussion is Dendrobium "Guadalcanal". Ames
(1947) relates the problem with this yellow and brown variation and
correctly included it with Dendrobium gouldii. Only its color gave basis for
a new name, but the more important problem lies in the manner in which
the name is written. Because the variation had a non-Latin name and
was capitalized, many thought that it was a hybrid and treated it as such
in successive crosses. It is an otherwise perfectly acceptable variation of
the standard Dendrobium gouldii concept. (Note: Hunt points out that
Dendrobium "Guadalcanal" is not the same as Dendrobium guadalcanalense
Guillaum. The former is a grex name, while the latter is a properly
defined species.)
There is also an alba form of Dendrobium gouldii appearing in the
background of crosses currently being produced in Hawaii, but I have not
been able to trace the plant.
Natural spread for this species is a difficult parameter to quote, as
measurements are also highly variable, but most forms seen by me seem
to fall near the measurements given below. Natural spread is 7.2 cm long
by 6-6.5 cm wide, the dorsal sepal 3-3.2 cm long by 0.5-0.6 cm wide,
lateral sepals 3 cm long by 0.5-0.6 cm wide, and the petals 4 cm long by
0.6 cm wide. The labellum is 3 cm long by 1 cm wide.
Distribution of the species and its variants was discussed in detail
above. The flowering season is variable with plants being in bloom much
of the year here in Texas and published reports suggesting that the main
blooming period is in the spring.
There are three awards to Dendrobium gouldii that are of interest.
Dendrobium gouldii (without a clone name) received a C.C.M. in 1959
with 82 points. This award was to a standard type and under the name
Dendrobium gouldii. In 1970, the species received a C.B.M. of 80 points
for a plant with three hundred flowers on twelve spikes, but the award
was to the owner of a plant with the name Dendrobium veratrifolium
'Elizabeth'. The last award was in 1978 where a plant labeled Dendrobium
lineale 'Jul-Mar' was awarded a C.B.R. as it carried twenty-seven flowers
on four spikes.
Dendrobium mirbelianum Gaudichaud 1826 Dendrobium mirbelianum is nearly as diverse and variable as Dendrobium
gouldii, but the literature offers us many clues to the solution of the name
problems found with this form. Thirteen synonyms grace this species,
though two of them are of no interest here (being in the genus
Angraecum), and, as in Dendrobium gouldii, they are again descriptions
of subpopulations from parts of a geographic cline. After describing
the typical forms of the species, I will address this variation problem
more completely.
Canes in this species are also quite variable; some reporting canes
only 30 cm tall, while others claim examples up to 200 cm. Most reports
seem to cluster about the 60-90 cm range. Canes are further
distinguished by stems that are terete near their bases but somewhat
flattened in their upper parts. The canes are leafy through much of
their length, with leaves that are ovate to oblong, and with rounded
tips. Flower spikes arise from leaf axils near the cane tips, with individual
canes commonly carrying up to three inflorescences. Reports vary
concerning floriferousness, with some variants having as few as five or
six flowers, while others
Dendrobium mirbelianum
claim to have seen fifteen or more per spike (and the synonymous form
"Dendrobium auranum" was stated to have "very many flowers").
The dorsal sepal is ovate-lanceolate and is either untwisted or only
very slightly twisted. Lateral sepals are quite similar but show more
tendency to twist than does the dorsal. Petals have narrow bases and
then expand to slightly spathulate shapes, and the entire petal is
frequently slightly twisted. Petals and sepals are definitely pointed.
The labellum of Dendrobium mirbelianum is also rather variable.
Lateral lobes are generally high, rounded and very prominent, though
in one variant (originally called "Dendrobium montisyulei") they are
said to be so small as to hardly differentiate them from the margin of the
median lobe. When all thirteen synonyms were examined, it seemed
that there was a continuum of change from the "montisyulei
Dendrobium mirbelianum, green form
Grower: Andree Millar Photography: Andree Millar
extreme form of lateral labellum lobes to those of the typical
"mirbelianum" type where they are broad and prominent.
The median labellum lobes are likewise variable, being reported
as oblong, ligulate, ovate-elliptical and lanceolate. Again when all
the variants are catalogued, there appears to be a continuum from
the clearly oblong shapes of "Dendrobium rimannii", through
tongue-shaped ligulate types like most of the variants to the ex-
treme elliptical shapes seen in "Dendrobium buluense". A glance at
the map shows that the ligulate forms are mainly from Timor
through Seram to southwestern New Guinea. The lanceolate types
are from southeastern New Guinea, while the oblong forms range
from New Britain in the east, and then extend along the northern
parts of New Guinea to Seram, Halmahera, Timor and eastern
Java.
To further illustrate this distribution pattern and to demonstrate
why it generated so many synonymous names, I would refer you to
the map for Dendrobium mirbelianum. As mentioned above, two of
the thirteen names for this species were simple errors and not worth
further mention, but the remaining eleven again help illustrate the
concept of the fragmented cline. All but one of the names used in
the paragraph below are synonyms, but I will show its original
distribution as perceived by the author of each synonymous
species.
"Dendrobium aruanum" Kraenzlin 1910 was reported from
south-central New Guinea and adjacent Aru Island (tan on the map).
"Dendrobium buluense "Schlechter 1914 was from eastern New
Guinea (yellow on the map). "Dendrobium calophyllum" Reichenbach
f. 1870 was defined from Timor, Ambon and adjacent islands
(purple on the map). "Dendrobium giulianettii" Bailey 1898 was
cited as occurring on parts of the northern coastline of New Guinea
(green on the map), while "Dendrobium montisyulei" Kraenzlin 1910
and "Dendrobium prionochilum " F. v. Muller 1894 are both from the
southeastern and eastern end of New Guinea (brown on the map).
"Dendrobium polycarpum" Reichenbach f. 1883 ranged through the
various Sunda Islands (pink on map), and "Dendrobium rimannii"
Reichenbach f. 1882 was scattered from Java, Timor and western
New Guinea (blue on the map). "Dendrobium robustum" Rolfe 1895
is from a number of sites in central New Guinea (red on the map), and
"Dendrobium rosenbergii" Teijsm. et Binnend. 1862 was restricted to the
island of Ambon (grey on the map). Dendrobium mirbelianum
Gaudichaud 1826, as originally defined, was located on eastern and
northern New Guinea, Ambon, Seram, Buru, the Mollucas, Timor,
Halmahera, Alor Island and New Britain (orange on the map).
Clearly these variations are parts of a common population and are
maintained by the mechanism of physical and genetic isolation.
Distribution of Dendrobium mirbelianum variants. See text for
explanation.
The median labellum lobes bear the usual, raised, keel-like
structures, but again with variation. Literature sources allow me to
suggest that those with five keels always present are from the middle
and northern parts of the geographic range, while in the southern parts
there are types that may only have three keels. The median keel is
always the longest and nearly always the tallest of the keels developed.
Margins of the median lobe are generally much undulated and
ruffled.
As might be expected from the discussion above, there are also a
number of color variants. Most forms seem to have some variety of
yellow. Examples are reported from clear pale yellow, pale yellow
with amethyst veins, bright yellow, yellow-green, yellow-green with
purple lines, yellow-brown, golden-brown, dark brown, and even a
report of a near-white form. Obviously color is not much use in defining
this species. The labellum is generally some variation on green or
yellow with darker veins, lines and keels.
The natural spread of Dendrobium mirbelianum is generally about 5
cm, with the dorsal sepal 2 cm long by 0.7 cm. wide, lateral sepals 2.5
cm long by 0.7 cm wide, petals 2 cm long by 0.8 cm wide, and the
labellum 2.3 cm long by 1 cm wide.
Distribution of the species and its variants is discussed in detail
above, so I will not repeat it here. Flowering seems to happen through
much of the year in its natural habitat, reports being found for
January, April, May, June, and October (with comments that the
species may bloom more than once a year). Authors state further,
however, that many forms are self-fertilizing and that the flowers
seldom last long. As the flower ages; its column changes shape,
sometimes allowing the pollen masses to reach the stigmatic surface.
This self-pollination may also be one of the keys to its numerous
varieties, since cross pollination lends uniformity to a population and
self-pollination preserves individual strains.
Dendrobium pseudoconanthum J. J. Smith 1926 In pleasant contrast to the last two species, here we have a form that
is clear-cut and precisely defined with no synonymous forms. This
species resembles Dendrobium conanthum, but it may generally be
distinguished by smaller flowers, darker colors, and a much larger
plant.
The type description states that the canes may be as much as 200 cm
tall, but Millar (1978) says that the New Guinea form may reach 500 cm
(16.5 feet tall). Womersley (1978) counters with a statement that there
are no undoubted forms from New Guinea and suggests that the
flowers found there may be some new species. This problem will
require additional study. The tall canes are cylindrical and thickened at
their bases, becoming thin and flattened at their tips. Leaves are broad
and smooth with somewhat recurved margins. The leaf tips show subtle
indentations suggestive of the bilobed condition seen on some of the
other species. Flower spikes arise from the upper parts of the canes and
extend laterally or only slightly above the horizontal. Each
inflorescence bears numerous flowers and several examined by me
carried twenty-five to twenty-eight blossoms.
The dorsal sepal is lanceolate with slightly undulated margins and is
strongly recurved. The lateral sepals are shaped very much the same.
Petals are linear-spathulate, with their borders both undulated and
twisted (J. J. Smith stated that the petals lacked undulations, but his
own type illustration shows them clearly).
Labellum lateral lobes are broadly semi orbicular, spreading widely in
a pleasing manner. Their inner surfaces are strongly marked with a
pattern of dark lines so interwoven that they form a reticulum. The
margins of the lateral lobes are smooth and without undulations. The
median lobe is oval to ovate and is pointed. When looking at the flower in
a casual manner, this shape is not evident immediately, as the tip is
strongly curved under the labellum. The labellum bears
three strong keels which extend out onto the disc, but which stop short of the
under-turned anterior portion of the median lobe. On many specimens there
appear to be additional keels where a pair of small ridges is added outside of
the main threesome, but these are much reduced and do not extend far
forward.
The flowers are basically greenish-yellow with a strong overlay of violet
dots, streaks and lines. The domination of violet and greenish tints gives the
flowers an apparent color of yellow with a brown overlay, but close
examination gives the true relationship. The presence of an uncolored strip
along the edges of the petals and sepals lends a handsome touch, and this
contrasting border carries through into hybrids.
The labellum and column are similarly colored with the same base tint
and violet overlay. Labellum keels are nearly white, have a crystalline granular
appearance and bear bright red-purple dots crowded closely along the
highest parts.
Natural spread of an average flower of Dendrobium pseudoconanthum is about
2.5-3 cm, with the dorsal sepal 1.5 cm long by 0.5 cm wide, lateral sepals 1.5
cm long by 0.5 cm wide, and petals 1.5 cm long by 0.3 cm wide. The labellum
is 2-2.5 cm long by 1-1.2 cm wide. No published descriptions for flowering dates seem to exist, but the plant
flowers during May in Louisiana. Dendrobium pseudoconanthum seems to be
ABOVE AND BELOW,
Dendrobium pseudoconanthum
Grower: T. R. Gallagher
Photography: C. R. Ossian
confined to Sulawesi, with possible records for adjacent parts of New Guinea.
Grower: Andree Millar Photography: Andree Millar
Dendrobium warianum
Dendrobium warianum Schlechter 1914
This last species in the subsection Mirbeliana is a modestly growing form
with bold, dramatic flowers. In nature the canes vary from 70 to 120 cm
tall, are thickened in the middle and taper to either end. The leaves are
smooth, elongate ovals that are held somewhat erect. The
inflorescences are erect, up to two feet long, and carry as many as
twenty-five well-presented flowers. As usual, these flower spikes
arise near the tops of the canes.
The dorsal sepal is rather oblong and blunt, with edges that are
somewhat undulated. Lateral sepals are much the same and all the
sepals tend to be strongly recurved. Petals are narrow at their bases but
become oblanceolate and dilated towards their tips. The petals lack the
undulations of the sepals and are slightly twisted.
Dendrobium warianum
Grower & Photographer: Andreé Millar
Line Drawings by C..R. Ossian
ABOVE, Dendrobium capra, from life ABOVE, Dendrobium gouldii, from life
ABOVE, Dendrobium mirbelianum, after Millar ABOVE, Dendrobium pseudoconanthum, from life
ABOVE, Dendrobium warianum, after Millar
The labellum lateral lobes are definitely oblong, though rounded
at their anterior ends. The outer edges of the lateral lobes are
irregular, with an undulated or scalloped margin. The median lobe
is elongate, oblong and pointed, with the margins strongly
undulated and ruffled. Three prominent keels arise at the base of
the labellum and extend forward almost to the tip of the median
lobe.
Color in this species is somewhat variable, though most forms
exhibit some aspect of yellow-green to brown. Usually there is a
yellowish base color with a prominent overlay of darker tones.
Sepals and petals carry five to eight bold, longitudinal lines that
interconnect with finer cross-bars, giving a somewhat reticulated
pattern to their front surfaces. The labellum is clearly yellow with a
median strip of white or off-white. Keels are dark brown to violet,
as are the veins on the lateral labellum lobes.
Natural spread in Dendrobium warianum is generally about 6 cm
with the dorsal sepal 2.5 cm long by 1 cm wide, lateral sepals 2.5 cm
long by 1 cm wide, and petals 3 cm long by 0.7 cm wide. The
labellum is 2.5 cm long by 1 cm wide.
Dendrobium warianum is distributed through northwestern and
northern New Guinea, and it seems to bloom through the
midsummer months in its natural habitat.
Part six of this series in the next issue of the A.O.S. BULLETIN will
discuss the subsections Taurina and Undulata, perhaps the most
extravagant and variable of all the Ceratobium dendrobiums. — 2805
Raintree Drive, Carrollton, Texas 75006.
REFERENCES
Ames, Oakes. 1947. The identity of Dendrobium
"Guadalcanal". Amer. Orchid Soc. Bull. 12:645-650.
Hunt. P. F. 1970. Notes on Asiatic orchids, V. Kew Bull. 24:
75-92.
Millar, Andreé. 1978. Orchids of Papua-New Guinea, an introduction.
Australian National University Press, 101 p.
Womersley, J. S. 1978. (review of Orchids of Papua-New Guinea, an
introduction: Andree Millar). The Orchadian, unpaged.