From “Tall Bearded Color Groupings” in The World of Irises by The American Iris Society, edited by Bee Warburton and Melba Hamblen:
“The Sass brothers saved dark segregates from their blue and violet lines and began intercrossing them, introducing The Black Douglas in 1934. Meanwhile, Nicholls (1933) was working a line of darks. He used Valor, of his own raising, withThe Black Douglas to produce Black Valor. Valor, combined with a seedling involving Morning Splendor, Souv. de Madame Gaudichau, and Alcazar gave Mata Hari and Smolder, both dark purples, the latter with a reddish underglow. The cross of these two sibs gave Storm King, introduced in 1940.
“Paul Cook crossed Blue Boy, an I. aphylla derivative, with a white diploid. Crossing the resultant seedling into a line of purplish reds from the dark Cinnabar and bitoned Seminole, he continued to linebreed and was rewarded with Sable several generations later. Often referred to simply as ‘the black iris,’ this famous variety astounded the iris world when it was first marketed in 1938….
“The concentration (or dilution) of anthocyanin in flower parts has profound effects on color. Petal extracts from dark purple or black irises have far more pigment in them than do the paler blues. If the delphinidin in the tetraploid tall bearded irises is under monogenic control, and there is a dosage effect, we could expect four different concentrations and therefore four different hues of blue violet, but this is hard to prove because other pigments are usually present in varying amounts.
“The background effect is probably responsible for the so-called reds and browns in the tall bearded irises. In varieties showing this effect, the anthocyanin in the cell sap appears red or brown due to the presence of carotenoid yellows in the plastids.”
From “These Things I Like” by John C. Slemp in Sunshine and Shadows: An Anthology of Life in Prose and Poetry, compiled by Monta H. Crane and Selma Shepherd Downey:
I like the simple things of earth:
A daisy on the lawn,
A violet by the garden gate,
A breath of air at dawn.
I like the lovely things of earth:
A rainbow in the skies,
A row of purple irises,
A pair of shining eyes.
I like the solid things of earth:
A firm and rugged tree,
A mammoth boulder on the hill,
A mighty ship at sea.
I like the lasting things of earth:
A faith that conquers strife,
A love that brothers humankind,
A strong and worthy life.
Hello!
This is the third of three posts with images of purple-toned irises from Oakland Cemetery that I photographed this year. The first post is Iris Purpleness (1 of 3) and the second post is Iris Purpleness (2 of 3).
Returning to the four-part comparison I shared in the first post, the galleries in this post include the tall bearded iris shown at the bottom right…
… whose heavily saturated purple and blue tones often approach black, especially in barely opened and newly opened buds where you are seeing what will become the bottom of a flower petal. If we zoom into a section of that iris’s standards just above the beard, we can get a better sense of how dark the colors really are, and how even the more shadowed regions still reveal the presence of blue and purple tones at levels close to — but not quite at — pure black.
The excerpt from The World of Irises at the top of this post — while a bit technical — is from a section of that book that goes into great detail about color development in irises, from around 1910 through the middle of the twentieth century. The authors spend a lot of time on the development of darker iris colors — differentiating them from the more commonly observed yellows and lighter purples — where breeding efforts produced more and more saturated colors approaching, and sometimes achieving, what we would characterize as solid black. In the excerpt, I linked to pages at The Historic Iris Preservation Society about individual irises that contributed dark color patterns, and you can see many other historically significant variants in the article The Development of Black Tall-Bearded Irises from The American Iris Society
The intensity of the pigmentation these developments produced is very evident in irises like the ones I photographed for this post; but plants with living, color-producing cells seldom produce single, unblended colors. The “background effect” mentioned in The World of Irises refers to the subtle variations of red and other colors that our eyes often miss when viewing these irises from a distance, yet the camera captures them quite effectively. Red, reddish-brown, or colors close to yellow and orange get threaded through some of the iris cells by the presence of carotenoids among the purple-producing anthocyanin. The influence of these carotenoid-based colors among a field of dark blues, dark purples, and blacks connects these newer irises to their ancestors, where the more common yellow and blue or purple colors were enhanced to produce intensely saturated colors and striking new color combinations.
Thanks for taking a look!
