Saturday, February 4, 2012

(Self) Pollinator of the Week: Cave hortulanus Impatiens capensis!

A jewel and a weed!

In my experience, New Year’s resolutions rarely make it through January. One of mine this year has been to expand my ‘social media’ output (in preparation for a symposium here in November). This means learning Google+, increasing my rate of posting at my blogs, and analyzing what other bug bloggers are doing. One thing I’ve noticed at other bug blogs is that those that maintain a high rate of posting tend to keep most posts short and sweet – a picture and a paragraph or two.
Jewelweed or Touch-Me-Not
 In contrast, my posts tend to be long and wordy. Inevitably, what should have been a pleasant weekend hour posting a picture or three and some ruminations on insect conservation morphs into a weeks-long struggle with the literature. These habits come from too many years of lecturing and are hard to break.
Ruby-throat hummer - likes Jewelweed and is probably a good pollinator
 Of course, this is the fun part of bug blogging – learning something new – and then telling someone about it. But I have folders filled with uncompleted posts that turned out to be far more complicated than I had expected or where some critical facts or photographs were unavailable or where I just ran out of free-time and energy. At least I got paid for lecturing: blogging is supposed to be a hobby (i.e. relaxing).
Attractive, but especially so to insects & hummingbirds
 So, here’s my New Year’s Resolution: learn to shut up and blog. Regular weekly posting themes seem to work well unless you run out of images (e.g. Sunday Sawfly). So, Friday Bug has been up two weeks now (and weeks of pictures to go) and today I am starting Pollinator of the Week.
Fly on flower: probably less than it seems
 For ‘Pollinator’ to make any sense, though, I will need to make clear the difference between an insect on a flower and pollination. The picture above is more likely of a root-maggot fly resting on a flower, than a pollination event. In previous years, I would have spent the next week or two trying to determine how much was known about anthomyiid flies and pollination. This year I am considering that approach irresolute.
Bumblebee & Jewelweed:
begatting as in the Bible
 The bumblebee (Bombus vagans), however, is clearly covered in pollen and doing its best to show the Jewelweed (aka Spotted Touch-Me-Not, Impatiens capensis) a good time. 
Seedpod - begat through an ecosystem service
That is what pollinations is all about – moving plant sperm (aka pollen) to receptive female parts (aka stigmas), and setting seeds. In the case of Touch-Me-Nots, these seeds come in a pod that at maturity will explosively discharge the seeds upon a touch - scattering most over good distances.
Touch-Me-Not touched (one seed retained)
 But if the soil is too dry or otherwise unsuitable, Jewelweed can suffer from erectile dysfunction – the flowers fail to open and release their pollen. Unfortunately, crosspollination is only an option for Jewelweed, not a necessity – they also indulge in cleistogamy – self-fertailzation within closed flowers.
Not yet open, but not cleistogamaous
 Spotted Touch-Me-Not is a great wildflower that is attractive to bees and hummingbirds. But it is also a weed. Thanks to its ability to explode its seedpod and fling its seeds far and wide, it will rapidly colonize any damp spot in the garden.
Cleistogamy - these flowers will never look better
 Even if the plant can only grow a few centimeters tall, it can generate new seeds through cleistogamy and continue its conquests. The only sign of salvation showed up last year – a sawfly found on the Jewelweed. Unfortuantely, finding an herbivore on an herb is no more informative than finding an insect on a flower. We didn’t observe the sawfly feeding and found only one, so possibly it was in transit to hibernating in the soil.
Sawfly on Jewelweed - maybe help is on the way
 Cave hortulanus is Latin for ‘Let the gardener beware!’ This applies to Jewelweed. Although not hard to pullout, Jewelweed is so prolific and self-regenerating, that your garden will soon have a permanent understory of bloomless weeds. Best leave this one in the wild.
Jewelweed where it belongs
Note: this is one of those posts that I started last year and never finished, but Wednesday Wildflower will also be making a comeback - hopefully in a less prolix form than this post.


  1. For a native 'weed', it's odd that I've never come across this one before. Was it originally on the Moose Pasture or did you introduce it?

    1. It's native over much of North America (check the USDA link in the name), but the botanist who described it mistakenly thought it was from South Africa - hence capensis.

      Until it blooms, it i quite innocuous looking. Check for Jewelweed along lake shores, on top of old beaver lodges, and margins of damp meadows.

  2. P.S. I am going to miss your long posts--the information you managed to dig-up was always interesting.