PROTECTING WISCONSIN'S BIODIVERSITY

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

Northern Wild Senna (Senna hebecarpa)

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Photo by Paul Drobot

 

Counties with Mapped NHI Occurrences

Northern Wild Senna (Senna hebecarpa), a Wisconsin Special Concern plant, is found on river banks, floodplains and moist shores as well as open forests and savannas. Blooming occurs from July through August, fruiting August through October. The optimal identification period for this species is August through October.

Cassia hebecarpa

 
 
 

Northern wild senna is a forb, 1-2m tall, with flowers that are yellow and 5-parted, but less pea-like than other genera in the Fabaceae family, 20-30mm wide and clustered to form a panicle at the end of the stems. Its seed pods do not readily open at maturity and are 7-12 mm long by 5-9mm wide. The space around individual seeds is mostly square, seeds flat with a depressed center. Leaves are pinnately compound, leaflets are 2-5cm long.

It is most likely to be confused with Senna marilandica, of which the joints of its seed pods are almost twice as wide as they are long, while S hebecarpa has joints that are about as wide as they are long. Senna marilandica also has a short, rounded petiolar gland, while S herbecarpa has a larger club-or ovate-shaped petiolar gland.

Roots and rhizomes. Blooming occurs from July through August, fruiting August through October.

Perennial. The optimal identification period for this species is August through October.

Northern wild senna prefers loamy or sandy soil and is found on river banks, floodplains, and moist shores as well as open forests or savannas.

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 locating landings, staging areas, or access routes on or near known populations.

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

Avoid site preparation that heavily disturbs herbaceous ground layer and soil, including bulldozing and furrowing, as well as grubbing and stump removal.

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.