Sometimes, curiosity just gets the better of you.
This is Kristin, one of our 2010 summer interns. Great young horticulturist. Has done public garden internships at Longwood and Polly Hill. Graduating from Penn State in December. Looking for full-time employment thereafter. Hint hint.
What Kristin is doing is counting and classifying pollinators on Pentas lanceolata. We had heard anecdotal tales about how many more pollinators were attracted to the older pass-around heirloom varieties of pentas than the newer seed-propagated varieties, but could find no real evidence let alone real-world data.
Also, I'm part of the Center for Pollinator Research at Penn State, and a pollinator preference project seemed like something that could be interesting and productive. So ... one of the many projects we threw at Kristin for the summer was to take some of the pentas plants which we had available, and begin to see if there might be something valid in the garden gossip. This is the first year, and her data will only be preliminary. If Kristin's results show that there might be something interesting, we'll set up a proper research study for 2011, complete with proper statistical design. We'll get our campus colleagues to participate in the design phase, and perhaps bring in an intern from campus to run the larger study.
It's not nearly as straightforward as I had originally expected. Pentas has two reproductive flower forms. A botanist would describe these forms as heterostyly. Many of the pentas varieties in commerce are pin forms, in which the styles are long and exposed, and the stamens remain deep in the corolla tube. The alternate form is the thrum form, in which the stamens are borne on long filaments, and the style is short so that the stigma is protected deep within the coroll atube. Primula vulgaris is the classic example of pin and thrum forms, but the phenomenon occurs widely.
Why the botany lesson? Well, if pollinators are more attracted to pentas pollen than to pentas nectar, then there may be a preference for the thrum (short-styled) form over the pin (long-styled) form. A good study design would account for this possibility --- which means locating and maintaining thrum forms. Unfortunately, these are not widely available in all pentas varieties. So this year's study is preliminary, and should generate enough information to let us plan the next study a little better.
But for now, K has a real interest in insects and pollinators, and is doing a great job collecting data. Once we get the data worked up, and if there is anything interesting in it, we'll be sure to talk about it here.