RUNYAN LAKE INC.

The lake association for the entire community of Runyan Lake
in Tyrone Township, Livingston County, Michigan.

**Invasive Species - Purple Loosestrife (Lythrum salicaria)**

Purple loosestrife is an invasive perennial plant that is spreading rapidly in North American wetlands, shorelines, and roadside ditches. Thick stands of purple loosestrife crowd out native plants and reduce food, shelter, and nesting sites for wildlife, birds, turtles, and frogs. After multiple introductions in the 1800s for bee keeping, as an ornamental plant, and in discarded soil used as ballast on ships, this European species has invaded nearly every U.S. state and at least six Canadian provinces.

Identification
Purple Loosestrife is a semi-aquatic perennial with showy pinkish-purple flower spikes; vegetation up to eight feet tall, from rootstocks, two to three feet in diameter. From its multiple stems, it produces as many as 2 million seeds from a single mature plant. These seeds, about the size of a grain of sand, blow and/or float to new areas where they absorb water, germinate, and grow. Prolific seed production, and the long life of the root crown, allows Purple Loosestrife to become a very dense monoculture. Purple Loosestrife provides no nutritive value to native insects, animals, or fish.

How It Spreads
Purple loosestrife spreads mainly by seed, but it can also spread vegetatively from root or stem segments. A single stalk can produce from 100,000 to 300,000 seeds per year. Seed survival is up to 60-70%, resulting in an extensive seed bank. Mature plants with up to 50 shoots grow over 6 feet high and produce more than two million seeds each year. Germination is restricted to open, wet soils and requires high temperatures, but seeds remain viable in the soil for many years. Even seeds submerged in water can live for approximately 20 months. Most of the seeds fall near the parent plant, but water, animals, boats, and humans can transport the seeds long distances. Vegetative spread through local perturbation is also characteristic of loosestrife; clipped, trampled, or buried stems of established plants may produce shoots and roots.

What You Can Do
Purple Loosestrife can be treated with herbicides (requires MDEQ permit) or be carefully removed to prevent the seeds from spreading. There are also biological control programs sponsored by Michigan Sea Grant and Michigan State University which provide beetles that consume the flowers of the plant, thus preventing the seeds with cause it to spread.

	Learn to recognize Purple Loosestrife. We have had quantities in the cove and southwest portion of the lake. Click here for a good article.
	Report any plants found to Runyan Lake Inc. so we can attempt to remove them.
	Inspect and carefully remove the plants, at least the tops with flowers, taking care not to drop flowers or seeds into the lake.
	Removed plants should be placed in a plastic trash bag and put out for removal by your refuse company. with your regular trash
	DO NOT BURN THE PLANTS as this will distribute the seeds.

Runyan Lake Inc. and its members have removed plants from several areas of the lake to control its presence.

Resources

Purple Loosestrife in Michigan (3.5MB) Wisconsin DNR Loosestrife Brochure Controlling Purple Loosestrife

Runyan Lake Inc.

PO Box 105, Fenton MI 48430-0105, USA

Copyright © 2007-2011 Runyan Lake Inc. All rights reserved. Updated 2011-08-22.

Reproduction in whole or in part in any form or medium without express written permission from Runyan Lake Inc. is prohibited.

Please view our: | Privacy Policy | Terms of Use | Site Map |