Foxglove Magic

Nurturing Peloric Plants

As I was working in the library garden this week, I was happily singing a little ditty with the refrain “We are marching to Peoria” and wondered aloud what on earth the marchers planned to do in Peoria? Another Friday Tidy volunteer kindly explained that they were headed for Pretoria, not Peoria, during the South African Boer war. I soon realized that the song stuck in my head was triggered by the foxgloves I was weeding around. A week or so ago, I had noticed a lovely mutation on several foxgloves growing at the library. The top bud on each stem in this small clump opened into a bowl shaped blossom rather than the usual tubular form.

I took a few pictures and through consultation with knowledgeable plant folks (thank you, PNW Plant Geeks!), I learned that the unusual flower form is the result of a more or less common mutation. The tendency of normally asymmetrical flowers to become symmetrical (or vice versa) was first described in 1744 by Carl Linnaeus, who codified the plant naming system still in use today. Linnaeus called the phenomenon ‘peloria’ after a Greek word that can mean either monster or prodigy (in the sense of being larger than usual). Ahah! These prodigious foxgloves were marching to peloria, a different drum indeed.

Preserving Pelorism

It seemed like an excellent idea to try to preserve the mutation by saving seed. Having experimented in the past with capturing unusual plant forms, I am aware that some variations are easier to preserve than others, and that some plants are more amenable to domestication. Millennia old landrace seed strains of heirloom tomatoes and traditional corn varieties are largely stable, but even so, to keep them true to type, they must be grown in groups and in relative isolation if their seeds will be saved. This particular clump of foxgloves is on its own, far from any kin, so there’s a chance that the seeds might contain the mutation.

I’ve been hearing anecdotally that many people have seen peloric foxgloves from time to time, so I’m enlisting friends who will mark any plants that present the mutation and save those seeds as well. An online search turned up a few commercial sources for peloric foxglove seeds, though all are sold out for this year. Commercial seed strains of all kinds are grown in strict isolation from anything that could potentially cross with the intended plants. Each season, the growing fields are scrupulously rogued to eliminate plants that don’t show the desired characteristics. Even so, gardeners who have raised plants from such strains report that not all of the resulting plants will display the desired mutation.

Raising A Horticultural Ruckus

When pelorism was first discovered, it caused quite a ruckus, since Linnaeus believed that genera and species were an expression of divine order and therefor could not possibly be changed. (Remember, this was over a hundred years before Gregor Mendel made his daring experiments with peas.) In foxgloves, generally only the terminal or top flower displays the peloric mutation. Some hundred and fifty years later, Darwin would speculate that this was because terminal buds have the most sap. Intrigued by pelorism, Darwin also observed that some species seem especially prone to pelorism; for instance, certain orchids frequently display peloric tendencies.

Darwin also found noted that while certain plants, such as foxgloves and snap dragons, had “a strong latent tendency to become peloric, there is also a still greater tendency in all peloric plants to reacquire their normal irregular structure.” Basically, that means that even if we manage to create a seed strain that produces a fair number of peloric plants, over time their offspring will tend to revert to their normal form. More recent research indicates that pelorism can be triggered by environmental stresses, including changes to a site (such as the removal of a shade-casting tree), changeable weather, and weather-related diseases such as mildew. With 100 year weather events occurring every few years now, this may be a splendid time to find peloric plants in our own backyards.

Create Your Own Seed Strain

Developing a (more or less) stable seed line can be a pleasing project for the home gardener, though the selection process can take years. I treasure a lovely strain of California poppy developed by the late Connie Caunt in her tiny garden in Victoria, B.C. The strain includes many shades of cream, pink and lavender, from palest baby ribbon pastels to vivid rose and near purple. However, even after many years of Connie’s patient work and my continuing efforts, genetically dominant orange poppies recur every season and must be removed lest they overtake the rosy ones. Similarly, creating a reliably peloric seed strain is probably not the work of a few seasons, thanks to that tendency to revert to the norm.

While most foxgloves are biennials, forming a leafy rosette in the first year and blooming the next, quite often in our climate they will rebloom a second year. If the original bloom stalks are removed, a whole cluster of shorter bloom stalks may appear a few months later or even the next season. While weeding, I found a plant tag identifying the peloric foxgloves as part of the Camelot series, a semi-perennial strain that has been blooming at the library for several years. Though they were definitely not peloric in the past, we’ll eagerly watch to see if these same plants bloom this way again next year.

Make Like A Bee And Hand Pollinate

Foxgloves are mainly pollinated by bumblebees, which are especially attracted to the color purple. The flowers have adapted to suit the chubby bumble body, lining the path to the nectar with little hairs that block smaller insect’s journey. You can play the part of the bumblebee by using a cotton swab to gently exchange the pollen from open flowers on peloric plants. To discourage bumbles from barging in with unwanted pollen from who knows where, remove the petals from your pollinated blossoms and mark the stems with yarn or soft ties.

According to Kew Gardens expert Paula Rudall, “Breeding experiments have shown that the terminal flower mutation in Digitalis is inherited as a simple Mendelian recessive, and can be reproduced from seed via either the peloric or normal flowers of the same plant, which are all fertile. Mutations that can be inherited and reproduce by seed could theoretically be capable of establishing new plant lineages…”

Onward!