never materialized. On their way they collected and/or identified more than 170 different species unknown to their supporters back East, a third of those found this side of the Continental Divide. That number would have been greater had a flood not destroyed a cache of plants at the Great Falls of the Missouri.
Today, the landscape Lewis and Clark explored looks much the same as it did in the 1800's. However, the mix of plant species found in some areas today varies dramatically from those noted by the Corps of Discovery. Invasive weeds, destructive plants that came from overseas, now crowd out native plant species along several of the pathways traveled by Lewis and Clark.
Ag researchers, a modern-day "Corps of Discovery," are studying ways to reverse this trend and examining new management techniques, including biological control, to restore native plant mixes.
Four Invasive Weeds
Leafy Spurge is a noxious weed invading thousands of acres in the northern Great Plains area alone. It has an extensive root system and is a prolific seed producer making it a difficult weed to control. Leafy spurge causes dehydration and weakness in cattle because of the toxic, milky-white latex that is found inside of the plant. At left is a photo of two NPARL researchers standing in a field of leafy spurge.
Saltcedar, also known as Tamarix, is a shrub or tree-like plant that soaks up as much as 200 gallons of water per day. Secreting salt, it forms a crust above and below the ground, inhibiting other plant life. It averages 10-12 feet in height, but can grow to be as tall as 20 feet. Make sure you watch out for this plant, because as it grows it becomes a mess of thickets acting like a wall, which are very scratchy and will tear at your clothes and skin. The places that you are most likely to see Saltcedar is near water because it cannot live without a lot to drink.
Purple Loosestrife is a European ornamental from the 1800's; it prefers wetlands and edges out native plants near waterways. Growing to an average height of 5 feet, it is noted for the purple flowers on its spikes. Purple loosestrife is equipped for cross pollination and a single plant produces millions of seed which remain viable for years. Check out the photo of purple loosestrife below. It might be pretty, but it isn't a friendly plant to have around.
Sulfur Cinquefoil, another foreign invader, is identified by its sulfur yellow, 5-petal flower and palmate leaf structure. It grows an average of 3 feet tall, and can take over areas in a wide range of environments. Animals and wildlife find it indigestible, and believe it or not, sulfur cinquefoil is very closely related to strawberries. So, research scientists have a hard time coming up with a chemical or bug to help get rid of it because the chemical or bug may also threaten strawberries.
In The End
All together, Lewis and Clark discovered a total of 178 plants new to western science during their epic journey across the continent from 1804 to 1806.
Many of the plants discovered and described by Lewis and Clark proved to be new species, and a few were new genera (for example, Lewisia and Clarkia).
Two thirds of those identified are included in a dried collection of more than 200 specimens now housed in the Lewis and Clark Herbarium at the Academy of Natural Science in Philadelphia.
Lewis and Clark also discovered a total of 122 new species of mammals, fish, birds and reptiles unheard of back East, including the antelope, coyote, western meadowlark, prairie rattler, and grizzly bear.
Lewis was the first to use ecological methods to describe the relations between various western animals and their environment. Among his discoveries: Prairie dogs never drink water.
Many animals now considered mountain denizens actually frequented the plains when the Corps of Discovery passed by. For example, Lewis and Clark first met the fierce grizzly bear along the Missouri River, now the northern border of Richland County.
Except for a few memorable notes about the abundance and virulence of the Missouri River's mosquito population, there were only casual references to insects in Lewis and Clark's journals. However, one tin box of insects was among the items sent from Fort Mandan to President Jefferson.
Click on the photo to the right to see more pictures from the NPARL dedication ceremony held on August 10, 2002. The ceremony featured a Lewis and Clark theme both indoors and out!
To read more about Lewis and Clark check out these links:
• Discovering Lewis & Clark
• Lewis & Clark's Historic Trail
• Lewis & Clark Trail Heritage Foundation
• Lewis & Clark in Montana
• Montana Kids.Com: Lewis & Clark
• National Geographic Kids: Lewis & Clark
• National Park Service: Lewis & Clark National Historic Trail
• PBS: The Journey of the Corps of Discovery
• Re-Live the Adventure of Lewis & Clark
• The National Council of the Lewis & Clark Bicentennial