Wednesday, October 10, 2012
The most obedient plant of them all!
Species name: Physostegia virginiana
Common name: false dragonhead, obedient plant
This species is common and native to much of temperate North America, with the exception of the United States and Canada west of the Rocky Mountains. It is tolerant to most growth conditions it would normally find in its natural habitat (periods of drought and of intense rainfall, both hot and cold temperatures, intense and indirect sunlight, etc.), which is one of the reasons why it's becoming a popular ornamental plant in native plant gardens. The flowers don't have that great a scent (it's not undesirable, but it's certainly not overly desirable, either), but they do attract many different kinds of pollinators to the garden which is never a bad thing (well, unless you're allergic to bees...). As you might be able to tell from the second picture, this plant is in the mint family or the Lamiaceae.
The flowers on this plant are incredibly amusing to play with, and that's how the second common name, the obedient plant, arose. Each flower is on a stalk within the inflorescence that has the ability to swivel left and right. This ability probably evolved as a response to being exposed to prolonged periods of high winds (prairies can be very windy, and since there are very few plants taller than this one that can shield the plants from the wind, a mechanism to protect the inflorescences from wind damage would be a desirable characteristic to have), but now is useful purely for entertainment. If you push the flower to one side or the other, it will stay that way. "Arranging" inflorescences in neat patterns is fun if you're out for a walk and come across a big patch of obedient plants. It will make the next person that comes along wonder what the heck is going on. The other common name of this plant, the false dragonhead, comes from the fact that the flowers of this plant look very similar to touch-me-nots, which are in the touch-me-not family or the Balsaminaceae. The easiest way to tell them apart is to look at the stem: the mint family all have square stems, while the touch-me-not family has round stems (often hollow and filled with liquid).