PROTECTING WISCONSIN'S BIODIVERSITY

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

Maryland Senna (Senna marilandica)

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Photo by Charles T. Bryson

 

Counties with Mapped NHI Occurrences

Maryland Senna (Senna marilandica), a Wisconsin Special Concern plant, is found in sandy prairies and oak woodlands, often near rivers. Blooming occurs early-July through late-August, fruiting early-August through late-September. The optimal identification period for this species is early-July through early-September.

Cassia marilandica

 
 
 

Maryland senna is an erect forb, 1-2m tall, with stems that are smooth or sparsely villous avove and lanceoate to linear stipules. It has an inflorescence of several axillary racemes. Buds are nodding, sepals unequal, petals are 10-15mm and slightly dissimilar. Fruit pods are 6-10cm long by 8-11mm wide, smooth or with scattered, minute, incurved hairs, and the joints about twice as wide as long. The seeds are nearly twice as long as wide, plump, with depressed center. Leaflets are commonly in 4-8 pairs, oblong or elliptic, and 2-5cm.

It can be distinguished from the more common S herbecarpa by its short-cylindric or rounded or dome-shaped petiolar glands (not oval or club-shaped), ovary appressed-hairy (not densely villous), joints of the pods (and seeds) about twice as wide as long (not equally wide as long), and somewhat fewer leaflets per leaf (4-8 pairs vs 6-10 pairs).

Blooming occurs early-July through late-August, fruiting occurs early-August through late-September.

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

Associated species include Betula nigra, Populus deltoides, Quercus bicolor, Arisaema dracontium, Veronicastrum virginicum, Teucrium canadense, Cornus racemosa, and Carex muskingumensis.

Maryland senna prefers sandy, roacky, or loamy soils and is found in sandy prairies and oak woodlands, often near rivers.

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.

Avoid locating landings, staging areas, or access routes in open sandy areas dominated by native grasses.

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.