Even orchids can suffer from an identity crisis
Orchids, The American Orchid Society Magazine
July, 1998
Naming his new species Cattleya aurea, Linden explained in some detail in Volume I of his famous book, Lindenia, how to identify C. aurea and distinguish it from Cattleya dowiana, “the other yellow-petaled species.” The lip of C. aurea, he said, is a “striated yellow, bordered with crimson purple,” while the C. dowiana lip “is crimson purple with touches of yellow streaks here and there.” The petals of C. dowiana, he continued, “are often purplish yellow, or even dirty yellow” while those of C. aurea are “always yellow — sometimes straw yellow, sometimes chrome yellow, but always a bright and pure shade of yellow.”
To show his readers exactly what he meant, for his introductory picture in Lindenia, Linden selected a brilliant-colored form of C. aurea with bright yellow petals and a lip with an unusually large amount of yellow. It was enough to make any potential customer want to buy one.
Linden obviously liked his new yellow-flowered Cattleya species, and with much splash and trumpet, he launched C. aurea into the horticultural world of the 1880s.
But not everyone accepted Linden’s new species. The British firm James Veitch and Sons, who received the first plants of C. dowiana from Costa Rica in 1865, considered Linden’s C. aurea a color form of C. dowiana and renamed it C. dowiana aurea.
Sanders and other British firms agreed with Veitch, and by 1894 when the seventh edition of Williams’ famous The Orchid Grower’s Manual was published, under “Cattleya aurea” the reader was told to see “Cattleya dowiana aurea.” By 1894, the identifying feature of C. dowiana aurea was simply its clear yellow sepals and petals that had no trace of lavender color in them.
As more and more plants of the yellow-flowered cattleyas were imported from Colombia and Costa Rica and the full range of color could be seen, even Linden began using the name C. dowiana to refer to some aureas. In Volume III of Lindenia (1891-94), Linden describes one of the most brilliant yellow forms ever found, the ‘Statteriana’ clone, as C. dowiana and he referred to it as “the variety aurea” in the text. But Linden didn’t give up Cattleya aurea completely, and in 1897 he published the now-famous double-page spread of seven
“Cattleya
aurea varieties.” This was his last hurrah, however, and in his final
volume of Lindenia, he admitted he could not tell whether the C. dowiana
‘Moortenbeckiensis’ (named for his own nursery) pictured on
page 138, was C. aurea or not, even though it came from Colombia.
If Linden himself sounded the retreat for Cattleya aurea more than 100
years ago, why do we still find some horticultural and botanical experts
pushing to make C. aurea a species again? The answer lies in C. dowiana.
Cattleya dowiana, in the broad sense, is unique among the unifoliate Cattleya
species not only for its yellow sepals and petals, but also because it
is found in nature in two widely separated areas. One is in Antioquia,
Colombia, in South America, the other about 600 miles away in Costa Rica,
Central America.
The brightest yellow clones of C. dowiana come from Colombia, including
most of the clear yellow-flowered types. By contrast, the C. dowiana from
Costa Rica has the largest amounts of lavender mixed with yellow in their
petals. It is tempting, therefore, to say the Colombian species is different
from the Costa Rican species based on their color alone.
The problem with splitting C. dowiana into two separate species based
on color, however, is that some of the same color forms exist in both
Colombia and Costa Rica. Not all Colom
bian
C. dowiana are aurea types. There are also plants with yellow sepals and
petals with some lavender in them, and these plants of C. dowiana look
the same whether they come from Colombia or Costa Rica.
Probably the most misunderstood characteristic of C. dowiana is its amazing
range of color. Contrary to common belief, C. dowiana is not just a yellow-colored
flower. Originally described in 1866 as having sepals and petals of a
“mellow straw color,” the tepal color actually ranges from
a reddish purple through tan and into various mixtures of yellow suffused
with lavender, to clear pale yellow-green, to clear yellow and even yellow-orange.
The lips of C. dowiana vary from dark crimson-purple with and without
gold veining, to mixtures of medium crimson with large yellow eyes, to
virtually all yellow. The amount of yellow in the lip can also vary from
year to year. One year the lip may have only a small amount of yellow,
or no yellow at all, and the next year it may have a large amount. Many
a hobbyist has been fooled into believing he or she has a spectacular
yellow-lip C. dowiana, only to find on the second flowering, there is
no yellow in the lip, only a few faint gold veins.
The amount of yellow in the lip can even vary from flower to flower on
a single spike. The recently awarded C. dowiana aurea ‘Kathlene’,
AM/AOS, is a good example of this phenomenon.
Lin
den’s
big mistake in introducing C. aurea was to place so much emphasis on the
difference in yellow color between C. dowiana and C. aurea. When flowers
with petals having lavender mixed with yellow began appearing from Colombia,
Veitch and others saw Linden’s C. aurea as merely a fine color form
of C. dowiana. Since all plants of C. aurea had different lip patterns,
Veitch couldn’t call them “variety aurea,” so C. aurea
became a type of C. dowiana, hence Veitch’s designation “Cattleya
dowiana aurea.” Remarkably, Linden’s own original description
in Lindenia of the lip color of the Costa Rican C. dowiana actually fits
a classic lip pattern of C. dowiana aurea from Colombia, of which C. dowiana
aurea ‘Meadowlark’ is an example.
If we ignore color and look at the other characteristics of the Colombian
and Costa Rican C. dowiana, those that might relate to geographical separation,
we find great similarity. Flowering season, general flower shape and size,
number of flowers per flower stem, plant size, fragrance, and intensification
of purple color in hybridizing are virtually identical in both the Colombian
and Costa Rican plants.
Some growers feel the aurea type C. dowiana from Colombia has more vigor,
is more resistant to rot and produces better hybrids than the non-aurea
types from Costa Rica. But, like color, this is not a hard-and-fast rule
and may relate more to the specific clones used in hybridizing than to
the general population. The most famous C. dowiana from Costa Rica is
variety ‘Rosita’, FCC/RHS (1900), which has an unusually large
amount of lavender in the sepals and petals. It is a vigorous grower and
has survived in cultivation longer than any clone of the Colombian aurea
types. The clone ‘Rosita’ was widely used in hybridizing and
produced some fine hybrids like Cattleya Thebes (Adula x dowiana ‘Rosita’)
and Cattleya Kittiwake (Brussels x Luegeae), so it cannot be said that
vigor, longevity and hybridizing superiority are a scientificbasis for
separating Colombian from Costa Rican C. dowiana.
Carl Withner in his book The Cattleyas and Their Relatives, relies primarily
on geography to separate C. aurea from C. dowiana when he says, “Based
on its segregated geographical distribution, it (C. aurea) is considered
a separate species in this book.” But geographical separation is
a difficult argument to use to establish a species if there are no other
real differences to go with it. Many plants of the same species are found
in widely separated places and the Central American C. dowiana may not
be separated by as much distance as we believe. Panama is the only country
that separates Colombia from Costa Rica, and C. dowiana has recently been
found in Panama. So where does this leave Cattleya aurea?
Ever since their discovery, the unifoliate Cattleya species and their
exquisite varieties have been such popular collectors plants that it seems
everyone wants to put his thumb in the Cattleya botanical pie. As a result,
the whole Cattleya genus is strewn with botanical and horticultural skeletons
that still haunt us. Linden tried to make a type of Cattleya labiata into
a new species when he described Cattleya waroqueana in 1890. He was not
successful in making it a new species, but Sander succeeded in making
Cattleya schroderae into a species in 1888 despite its close similarity
to Cattleya trianaei, so our problems with Cattleya aurea are not unique.
The majority of horticultural and botanical authorities today favor using
the name C. dowiana for both the Costa Rican and Colombian yellow-petaled
Cattleya species, and the facts seem to support their view. The International
Authority for the Registration of Orchid Hybrids also feels this way.
It does not recognize C. aurea as a species and will not register a hybrid
with C. aurea as a parent. Sander’s List of Orchid Hybrids therefore
shows no hybrids using C. aurea.
But if someone can come up with a substantive difference between the C.
dowiana from Colombia and Costa Rica and C. aurea becomes a species in
its own right, I wonder how we will describe the clear yellow-petaled
type we now call “Cattleya dowiana aurea.” Since not all Colombian
C. dowiana are aurea types, we will need some way to separate the clear
yellows from the lavender yellows. Perhaps hobbyists will call their old
Cattleya dowiana aurea, “Cattleya aurea aurea,” or invent
a new name for golden yellow.
In the meantime, our best advisor on nomenclature may be William Shakespeare.
Shakespeare was a rose lover, not an orchid fancier, but when he asked
“What’s in a name? A rose by any other name would smell as
sweet,” he reminds us that it may not matter what we call the beautiful
yellow-flowered Cat-tleya species from Colombia as long as we all understand
what plant we are talking about. For now at least, it seems best to call
it Cattleya dowiana.
A. A. (Art) Chadwick has been growing Cattleya species for more than 50
years. During the late 1940s, he grew large numbers of Cattleya dowiana
for commercial cut-flower production. Art is still actively hybridizing
with both Colombian and Costa Rican C. dowiana to study their genetics.
He is an outside director of Chadwick & Son Orchids in Powhatan, Virginia.