Saturday, October 2, 2010

The Book of Impatiens

From the Balsaminaceae or Touch-me-not Family comes this wonderfully exciting plant: Impatiens capensis. It is also known under the names of Orange spotted Jewel-weed and Orange spotted Touch-me-not.

At this time of year, it is a delight to encounter this plant because it's capsules are ready and they hold quite a surprise for the curious observer. But let's keep the best for last.

I. capensis is a widespread plant; I have encountered it in moist woods, brooksides and wet roadside ditches in Montreal, New York, and Virginia beach.

Gleason and Cronquist (1991) describe the range as such: Newfoundland and Quebec to Saskatchewan to South Carolina, Alabama, and Oklahoma – East Coast to about the middle of North America.

Impatiens flowers are easy to identify due to their shape. The spurred sac-shaped flowers droop upside down from slender pedicels. The opening if formed by three petals, one larger than the others making up the top lip (or bottom considering it's upside down). Many flowers have a radial symmetry (actinomorphic) meaning they can be divided in more than 2 equal parts. Jewel-weed flowers have bilateral symmetry (zygomorphic); you can split it into two equal parts much like the human body. If you want to read more about floral symmetry, click here.

Even without it's distinctive orange speckled flowers, Jewel-weed is easy enough to identify; alternate, softly toothed and delicately veined leaves upon a ghostly translucent stem with darkened nodes. I have seen it with a stem as thick as my finger and so thin it's a miracle it can stand at all. All you need is to see it once and from then on, they jump out at you.

I. capensis is the Aloe Vera of native North America. I rub the juice on insect bites to stop the itch. You can mix it with Vaseline (or fat) to make an antiseptic and hydrating cream
. My recent forest walks have led me to observe a funny tendency: when I come across a patch of Poison Ivy there is a patch of Jewel-weed not far from there. I haven't tried walking through Poison Ivy and rubbing Jewel-weed on it but maybe that's what nature is trying to tell me. That, or they tend to grow in similar conditions which not as romantic.

The main reason I love to meet this plant is due to its seed dispersal method. Impatiens produces elongated oval-shaped capsules which dangle so alluringly amongst the leaves and flowers. When you reach out to touch these little green pods they explode, shooting their seeds aloft. Believe you me, hours upon hours of fun. This particularly exciting dispersal method explains why they belong to the Touch-me-not family. The capsule twirls up into 4-5 curls, which once surrounded four seeds. Depending on when the capsule bursts, they can be green or a dark striated brown. When looking for capsules, pick the biggest and plumpest ones. You don't need to squeeze forcefully, a gently touch suffices to set off the mechanism. Try and catch the seeds if you can. The seeds will land a couple meters away from the parent plant and lay dormant until the following spring.

They are not the only ones that propel their seeds. Dwarf mistletoe (Arceuthobium)
, a parasitic plant, gathers up hydrostatic pressure in the fruit and shoots out the sticky seeds at 100 Kilometers per hour (65 miles an hour). Where dispersal agents are concerned, plant scientists have divided them in three large categories: wind, water, and animals. Propelled seeds are considered a form of wind dispersal along side dust-like orchid seeds, winged schizocarps of maples and the plumelike pappus or parachutes of the dandelions.

Keep your eyes peeled and fingers ready!
Take care!


Gleason, H.A & Cronquist, A.. Manual of Vascular Plants of Northeastern United States and Adjacent Canada - 2nd Ed.. Bronx, NY: The New York Botanical Garden Press, 1991.

Raven, P.H., Everet, R.F. & Eichhorn, S.E.. Biology of Plants - 7th Ed.. New York: W.H. Freeman and Company Publishers, 2005.

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