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.