PROTECTING WISCONSIN'S BIODIVERSITY

 
 
   
 
Scientific Name Common Name Global Rank State Rank Federal Status WI Status

Prairie Milkweed (Asclepias sullivantii)

Aspl_sull2.jpg

 

 

 

 

8681.jpg

Photo by William S. Alverson

 

Counties with Mapped NHI Occurrences

Prairie Milkweed (Asclepias sullivantii), a Wisconsin Threatened plant, is found in moist prairies. Blooming occurs early-June through early-July, fruiting throughout July. The optimal identification period for this species is early-June through early-July.

 
 
 

Prairie milkweed is an erect forb, up to 1m tall, with two or more flower heads that extend from the upper stem. Flowers are purplish-rose colored with 9-12mm long lobes and 5mm long hoods. Its fruit are hairless pods that may be covered in wart-like bumps and are bent abruptly downward. Leaves are thick hairless, broadly elliptic to ovate to oblong, 10-15cm in length, sessile, and usually erect and ascending.

It can be distinguished from other milkweeds by its leaves, which are glabrous, sessile, and erect or ascending on main stem, but do not have wavy margins.

Blooming occurs early-June through early-July, fruiting throughout July.

Perennial. The optimal identification period for this species is early-June through early-July.

Associated species include Andropogon gerardii, Aster ericoides, Eryngium yuccifolium, Petalostemum purpureum, Silphium species, Solidago rigida, Liatris aspera, and Veronicastrum virginicum.

Prairie milkweed is found in moist prairies with moist to mesic, rich soils.

Avoid known individual plant locations and conduct operations elsewhere when they are least likely to cause damage. Ideally, this would involve frozen, snow-covered ground. However, in areas of the state where frozen conditions are unreliable, very dry soils late in the growing season might be the best available alternative. Consult with a biologist, if needed.

Avoid broadcast spraying of herbicides and use care with spot spraying.

Prescribed burns and/or brushing may be beneficial, dependent on local site conditions and burn frequency. Rotational burns with annual unburned refugia may be preferred.

Maintain and restore open habitat through selective clearing and brushing.

Species of Greatest Conservation Need (SGCN) are associated with habitats (or natural communities) and places on the landscape. Understanding relationships among SGCN, natural communities and ecological landscapes help us make decisions about issues affecting SGCN and their habitat and how to respond. Download the Wildlife Action Plan association score spreadsheet to explore rare species, natural communities and ecological landscape associations

Conservation actions respond to issues or threats, which adversely affect species of greatest conservation need (SGCN) or their habitats. Besides actions such as restoring wetlands or planting resilient tree species in northern communities, research, surveys and monitoring are also among conservation actions described in the Wisconsin Wildlife Action Plan because lack of information can threaten our ability to successfully preserve and care for natural resources.