As Easter, 2011 finally arrives here in this slow-starting Spring, I've been given a present in the garden to watch over. A white sport appeared on my 'Sensation' Lilac this year amidst all the deep purple, white-edged blossoms. This year, the Equinox Gods must be rewarding my earlier offerings to the start of Spring.
I appreciate the gift, but I would feel more special about it if a quick search didn't reveal that white sports from 'Sensation' are not especially rare. There are several pictures of these sports on the Internet, and indeed, a webpage about plant sports by Professor Janna Beckerman from Purdue University's Plant Diagnostic Lab included a white 'Sensation' sport as a common example.
'Sensation', for those gardeners who aren't familiar with it, is a popular lilac in commerce and in gardens because of the unique purple and white look to the blossoms that is commonly described as a "picotee." Picotee is derived from the word "picot," which is a series of small embroidered loops forming an ornamental edging on some ribbon and lace, and the word "picotee" actually is defined as a carnation with pale petals bordered by a darker color. 'Sensation' then, I suppose, should be more accurately described as a reverse picotee. 'Sensation' also has nice heart-shaped foliage, but it is a rather stiff bush, growing 8-10 feet tall and wide, with strong, hearty branches that tend to be a little more sparse than most lilacs. To my amusement, 'Sensation' is labeled at many online nurseries as a "new" introduction, but it is actually an old lilac, introduced in 1938 by Eveleens Maarse. According to Jennifer Bennett in her 2002 book Lilacs for the Garden, it was a genetic mutant of lavender-colored 'Hugo de Vries' that occurred when the Maarse greenhouse in Holland was forcing lilacs for Christmas. John Fiala, in Lilacs: A Gardener's Encyclopedia, lists it in a section with lilacs of "special and unique color classifications," and describes it as "outstandingly effective and unique." Alongside the white sports, 'Sensation' has also been known to revert to the plain purple form resembling 'Hugo de Vries'.
For the scientifically-minded, the proper term for the mutation that led to 'Sensation' is a "periclinal chimera," which is a plant composed of cells of two distinct genotypes separated into distinctive zones. Periclinal chimeras, as opposed to the other categories of chimera (mericlinal, and sectorial chimeras), are important because the mutations are stable and can be vegetatively propagated. Thornless blackberries are perhaps the best known result from the formation of a periclinal chimera. In the case of my white 'Sensation' sport then, the white flower genotype tissues have separated to give me a present.
Knowing all that, however, makes my own 'Sensation' sport no less of a miracle to me. I'm going to watch it, and if it doesn't go through an ugly brown phase as so many white lilacs do when they fade, I'm going to try to propagate it. Maybe someday I can have a part in releasing a lilac that will be named 'Easter Sensation.'