Friday, August 24, 2012

A Prairie Birthday

In one of Aldo Leopold's essays in A Sand County Almanac, he discusses the idea of a Prairie Birthday. He points out that each week during the months of April to September gives way to the blooming of new wildflowers on the prairie and how these "birthdays" should be celebrated. There is one particular flower he discusses the most; and while we may have missed the celebration of its first bloom in July, the Compass Plant is still in full bloom.

Silphium Laciniatum

The official name of the compass plant is Silphium laciniatum, but is sometimes referred to as the compass flower or rosinweed. Even though these plants might be related to the sunflower, don't get them mixed up! One major difference between the two plants is the sticky sap, or rosin, you can find in in the compass plant's stem - hence the nickname rosinweed. This rosin was once used by Native American children as chewing gum to clean their teeth and freshen their breath. Compass plants can grow to be around 10 feet tall with leaves that are 15 - 24 inches in length! And for every inch above ground, imagine that their roots are extending about the same distance below! The bright yellow flowers at the top of the stem are more modestly-sized, ranging from 2 to 4 inches across. You can find these lovely plants anywhere in the East-Central region of North America, mostly in tall grass prairies.

Sense of Direction

While the nickname "rosinweed" has an obvious origin, the name "compass plant" might not seem to make much sense with this flower at first. This name derives from the discovery that the leaves on the plant almost always point in the North-South direction (the key words are "almost always" - so don't get rid of your orienteering tools just yet). Once early settlers on the central plains realized this, they were able to use the plants as a guide to help them know where they were going - just like a compass!
Compass Plant at the
Aldo Leopold Nature Center

These plants have a long history in North America, being used as herbal medicines and teas by the Native Americans, and then as compasses by American settlers. No wonder Aldo Leopold was so amazed by these resilient plants! He appreciated these plants as a symbol of Wisconsin's native prairie, and you can enjoy these beauties too. Go exploring in a nearby grassland, prairie, or park. See if their leaves really can point you in the right direction. The Aldo Leopold Nature Center is a great place to begin your quest - their prairie is blooming full of compass plants these days - or take a walk through the UW Arboretum or Olbrich Botanical Gardens for a more extensive feel of the native prairie plants we have here in Wisconsin.

Thursday, August 2, 2012

What's That I Smell?

Much to the relief of people around Wisconsin, rain has finally fallen to break this terrible drought! With it has come fresh green grass and flowers, along with something very familiar to us: the smell of rain.

There's something in the air

That smell of fresh fallen rain after an extremely dry couple of days is something so unique, it's hard to not recognize it. In fact, the smell is so unique that it even has it's own name: Petrichor, the smell of rain on dry earth. While we automatically associate this scent with rain, the rain is not what produces it. The smell is actually derived from an oil that is excreted by certain plants during a dry period. This oil is then absorbed by the surrounding soils and rocks. When it rains, this oil is released into the air along with Geosmin, thus producing the well-known aroma.

What is Geosmin?

Geosmin literally means "earth smell" and is an organic compound produced by several different kinds of microorganisms. This scent is very earthy and can be detected by humans in very little concentrations. This compound is what attributes the earthy flavor of beets and the muddy smell of bottom-dwelling freshwater fish (like catfish). Geosmin is most commonly associated with rain and is the main contributor to its smell.

While rain can sometimes put a damper on your outdoor plans, there are still lots of fun things you can do. During a thunderstorm, have your kids count how many seconds it takes for it to thunder after a lightning strike. Every five seconds it takes for the sound to arrive to your ears is how many miles away the heart of the storm is. (Learn more about calculating storm distance here.) After it rains, go on an adventure. Nature can be a completely new place after a good rainfall, so take your kids out on a short hike and have them discuss or record what they see, smell, or hear. Go puddle jumping, rescue earthworms from roadways, or see if you can find any new plants, bugs, or other critters that weren't around before. No matter the weather, there are always things to do in Nature!