Thursday, June 9, 2011

The Foxglove Beardtongue Story

Having the luxury to observe a plant population over a long period of time can allow ordinary plants to acquire special characteristics. It’s not a change in the physical form of the plant that causes notice. What you come to appreciate are the annual changes in the population size or blooming variations or other similar factors that make a plant become an individual. My population of Foxglove Beardtongues, Penstemon digitalis, is a good example.

I added Foxglove Beardtongue to my list of Blue Jay Barrens plants around 18 years ago. My notes were not very lengthy concerning the discovery. A small circle on the map and a comment identifying “about 100 blooming plants” was all I said. In my mind, I was defining this population in fairly rigid terms. I believed that I was describing a situation that had remained relatively unchanged for several years into the past and would remain the same for many years into the future. Having made my note, I moved on to find what else there was to see.

The shock came the following year when I walked past the site of about 100 blooming plants, but saw no blooms. I was busy with something at the time and didn’t stop to investigate further. I assumed it was still a bit early for the plants to bloom. I made a mental note to check again a little later. I wasn’t too concerned about their absence because I had already documented about 100 blooming plants at that spot. I made the note myself, so it had to be true.

A couple of weeks later I went by for another check of the Foxglove Beardtongue. Once again, no blooms were evident. Now I assumed that something had happened to the flower buds to keep them from opening. An examination of the plants would clear up the mystery, so I began looking for plants. A thorough search revealed no plants, no parts of plants, no stalk stubs where plants had been. There was no evidence at all that my population of about 100 blooming plants had ever existed. Now, how was I expected to manage plants when they behaved as erratically as this?

It was four years before a Foxglove Beardtongue once again bloomed at this site. Since that time, the population has increased, decreased, disappeared and moved around the clearing. I don’t know why this occurs. Being a perennial plant, I thought it might persist for a longer time. It’s just something that adds personality to this population as well as one more factor to be considered in the overall management plan.


  1. Interesting..I did not know the foxglove did this..I do know the milkweeds can do this.Iv'e dug up the root systems and found them intact below the surface and yet some years no plants emerge.Many variable possible triggers,temp,moisture,soil ph?,nematodes?lack of storage of enough energy from previous season?

  2. There are many possible factors, Michael. Or it could be various combinations of different factors. It's nice to have a hobby that guarantees you’ll never run out of puzzles to ponder.

  3. Are there black walnut trees in the area?

  4. The nearest black walnut is about 400 feet away.