Author:
David J. White - R.R. #3 - Lanark, Ontario - KOG IKO
31 March 1996
Report prepared for the Canadian Wildlife Service, Ottawa

Table of Contents
ABSTRACT

ACKNOWLEDGMENTS

1.0 INTRODUCTION
1.1 Milkweeds and the Monarch Butterfly
1.2 Description of the Milkweed Genus
1.2 Biological and Economic Significance of Milkweeds

2.0 SPECIES ACCOUNTS
Asclepias exaltata (Poke Milkweed)
Asclepias hirtella (Milkweed)
Asclepias incarnata (Swamp Milkweed)
Asclepias lanuginosa (Milkweed)
Asclepias ovalifolia (Oval-leafed Milkweed)
Asclepias purpurascens (Purple Milkweed)
Asclepias quadrifolia (Four-leaved Milkweed)
Asclepias speciosa (Showy Milkweed)
Asclepias sullivantii (Sullivant's Milkweed)
Asclepias syriaca (Common Milkweed)
Asclepias tuberosa (Butterfly-weed)
Asclepias variegata (Variegated Milkweed)
Asclepias verticillata (Whorled Milkweed)
Asclepias viridiflora (Green Milkweed)

3.0 NOXIOUS WEED LEGISLATION
3.1 Weed Legislation Summary
3.2 Potential Impact from Weed Legislation

4.0 INFORMATION SOURCES
4.1 References
4.2 Collections Consulted

LIST OF TABLES

TABLE 1: Summary of Milkweed Provincial Distribution and Status
TABLE 2: Summary of Weed Legislation Affecting Milkweeds

LIST OF FIGURES

Figure: North American distribution of Asclepias exaltata
Figure : North American distribution of Asclepias hirtella
Figure: Ontario distribution of Asclepias hirtella
Figure: North American distribution of Asclepias incarnata
Figure : North American distribution of Asclepias lanuginosa
Figure: Manitoba distribution of Asclepias lanuginosa
Figure: North American distribution of Asclepias ovalifolia
Figure: Ontario distribution of Asclepias ovalifolia
Figure: British Columbia distribution of Asclepias ovalifolia
Figure: North American distribution of Asclepias purpurascens
Figure: Ontario distribution of Asclepias purpurascens
Figure: North American distribution of Asclepias quadrifolia
Figure: Ontario distribution of Asclepias quadrifolia
Figure: North American distribution of Asclepias speciosa
Figure: North American distribution of Asclepias sullivantii
Figure: Ontario distribution of Asclepias sullivantii
Figure: North American distribution of Asclepias syriaca
Figure: Saskatchewan distribution of Asclepias syriaca
Figure: North American distribution of Asclepias tuberosa
Figure: North American distribution of Asclepias variegata
Figure: Ontario distribution of Asclepias variegata
Figure: North American distribution of Asclepias verticillata
Figure: Ontario distribution of Asclepias verticillata
Figure: Saskatchewan distribution of Asclepias verticillata
Figure: North American distribution of Asclepias viridiflora
Figure: Ontario distribution of Asclepias viridiflora

ACKNOWLEDGMENTS

I would like to express my appreciation to a number of people who helped with this study.

First I would like to thank Dr. Erich Haber, National Botanical Services, Ottawa for support and advice. Erich also conducted the library computer database searches and located some literature. Gerry Lee, Chief of Habitat Conservation, Canadian Wildlife Service, Hull, administered the contract and provided helpful contacts.

Information on weed act legislation was kindly provided by the following people: Tom Hodgson of Agriculture Canada, Ottawa; Walter Yarish of Alberta Agriculture, Edmonton; Dave Ralph of the Ministry of Agriculture, Fisheries, and Food, Kamloops, British Columbia; Jo Anne Buth of Manitoba Agriculture, Carman; Kevin McCully of the New Brunswick Department of Agriculture; Doug Doohan of the Nova Scotia Department of Agriculture, Truro; Sherry Ross of the Prince Edward Island Department of Agriculture, Fisheries, and Forestry, Charlottetown; Doug Billet of Saskatchewan Agriculture; Pierre Lavigne, Ministere de le'Agriculture, des Pecheries et de l'Alimentation, Sante-Foy, Quebec; and Howard Lang, Ontario Ministry of Agriculture, Food, and Rural Affairs, Guelph.

Mike Shchepanek, Canadian Museum of Nature (CAN), Ottawa, facilitated access to the library and herbarium at CAN. Cathy Keddy, Carleton Place, Ontario, provided background information on weed control legislation. Gisele Mitrow, Agriculture Canada (DAO), Ottawa, helped with access to the library and herbarium at DAO. Don Lafontaine, Agriculture Canada, Ottawa provided background information of the Monarch Butterfly.

Funding was provided by the North American Wetlands Conservation Council (Canada) and Ducks Unlimited.