by Tom Waters
Dwarf bearded irises may be found growing wild throughout
much of southwestern Europe, from Spain and Portugal, through southern France,
and into northern and central Italy. Through the centuries, different botanists
have encountered them in different localities and assigned different names to
them: Iris chamaeiris, I. italica, I.
olbiensis, I. lutescens, I. virescens, I. subbiflora, I. bicapitata.
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| Iris lutescens, raised from seed |
By the twentieth century, it was clear that most, if not
all, of these were really irises of the same species. Gardeners were most
familiar with those from southern France, going by the name of I. chamaeiris, so began referring to the
whole species as the “chamaeiris complex”. But the rules of botanical
nomenclature require that synonyms be resolved by using the earliest published
name for the species. In this case, that honor goes to I. lutescens, the name used by Lamarck in 1789. This is now the
correct name for all these irises, with the exception of two irises at the
extremities of the species’ range, I. subbiflora in Portugal and I. bicapitata in the Gargano peninsula
of eastern Italy, which are regarded by many (though not all) botanists as
distinct species in their own right. Even if these are not regarded as
belonging to I. lutescens, they are
indisputably very close relatives.
I. lutescens is a
delightfully varied species. The flowers are most often yellow, cream, or
violet, but there are near-white forms, purples, blends, and bitones. In
height, they range from about 6 to 12 inches (15 to 30 cm). The stem is
unbranched, with one or two terminal flowers.
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| Iris lutescens 'Bride' (Caparne, 1901) |
Until the second half of the twentieth century, I. lutescens and a handful of its accidental hybrids with
other species were the only dwarf bearded irises known to gardeners in western
Europe and North America. Named cultivars were produced by the firm of Goos and
Koenemann in Germany, by W. J. Caparne in England, and later by Hans and Jacob
Sass, among others, in the US. At this time, the modern dwarf and median
classes did not exist, so there was no distinction between miniature dwarfs and
standard dwarfs; they were all simply “dwarf bearded”, and spanned the whole
natural height range of the species, which straddles both of the modern
categories.
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| Iris lutescens 'Path of Gold' (Hodson, 1941) |
Although many people grew a few dwarfs, appreciating their charm
and early bloom, almost all the attention of iris enthusiasts in the first half
of the twentieth century was focused on the tall bearded. The dwarfs were
rather taken for granted, by both gardeners and hybridizers. That began to
change with the formation of the Dwarf Iris Society under the leadership of
Walter Welch in the 1940s. Welch and his friends were determined to learn all
they could to advance dwarf hybridizing, and their interest went beyond the I. lutescens cultivars to investigate
other dwarf species, such as I. pumila from
eastern Europe.
I. pumila is a
diminutive species, about half the height of I. lutescens, single-flowered and almost stemless. Robert Schreiner
had imported some seeds in the 1930s, and the species gradually became available
to the new dwarf hybridizing enthusiasts. The turning point came in 1951, when
Paul Cook in Indiana, who had exchanged his pumila
pollen for TB pollen from his friend Geddes Douglas in Tennessee, introduced
the first pumila/TB hybrids: ‘Baria’, ‘Green Spot’, and ‘Fairy
Flax’. Although technically “intermediates” (as the word was used then, it
meant a hybrid between dwarf and tall bearded irises), these new irises were no
larger than many I. lutescens dwarfs,
even though they often had a branch and a total of three buds! This launched a
vigorous debate about classification, which led ultimately to the formation of
the Median Iris Society and the four median classes we have today. The SDB
class was created to accommodate the new pumila/TB
hybrids and the taller I. lutescens
cultivars, with the MDB class left for the “true dwarfs”, with a maximum height
limit of 10 inches, later adjusted to 8 inches.
From the 1960s on, the SDBs from pumila/TB breeding totally dominated the world of dwarf irises. These
SDBs carry an extraordinary genetic legacy (dramatic spot patterns from I. pumila, pinks and plicatas from TBs,
not to mention more modern form). There was no interest any more in producing
more of the overly familiar yellow or violet I. lutescens cultivars. Even the MDB class was taken over by the
new SDBs. Most MDBs from the 1960s onward were produced by crossing the new
SDBs back to I. pumila, or
(especially in recent decades), just selecting irises from SDB breeding that
happen to be under the height limit.
I. lutescens, once
the very archetype of the dwarf bearded irises in gardens, is now a curiosity
known only to species enthusiasts.
Is there any hope for a
lutescens renaissance? At first blush, it would seem unlikely. The modern
SDBs have been so developed by decades of dedicated hybridizing that they would
seem to have nothing to gain (and much to lose, in terms of present-day
expectations of the class) by the injection of I. lutescens into hybridizing lines.
If I. lutescens is
to be heard from again in dwarf hybridizing, the opportunity may be in the MDB
class. Some MDB enthusiasts have been grumbling of late that the class has been
taken over by short SDBs, and is losing something of its distinctive charm.
There may be some niche here for MDBs with more of a “wildflower” look,
breaking away from the stiffness, width, and ruffling that comes from pure SDB
breeding. Just as the MTB class has given a home to the simpler, more modest
look of the diploids, perhaps there is an opening for more “retro” MDBs. I. lutescens is fully fertile with SDBs
and their MDB progeny, and might add a breath of fresh air to a class that is starting
to feel overworked.
Everything old is new again?
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| Iris lutescens campbelli |
The World of Irises is the official blog of The American Iris Society. Now in its 99th year, The American Iris Society exists to promote all types of irises. If you wish to comment on a post, you can do so at the end of the page and the author or the editors will reply. If you wish to learn more about The American Iris Society, follow the link.
