Wisconsin's rare plants

Round-fruited St John's wort is an erect forb with a branched and usually compact inflorescence, sepals 2.5-5mm, petals 5-9mm, 45-85 stamens, and 3 or 4 minute stigmas. Its fruits are ovoid, 5-7mm, slender beaked, strictly unilocular, seeds are 2-2.7mm. Its leaves are linear oblong to narrowly elliptic, 3-7cm long by 5-15mm wide, with or without evident lateral veins, acute or obtuse, and tapering to the base.

Rhizomatous. Blooming occurs late-June through early-August, fruiting late-July through late-August.

Perennial. The optimal identification period for this species is late-June through late-August.

Associated species include Quercus macrocarpa, Salix species, Potentilla arguta, Eryngium yuccifolium, Ratibida pinnata, Cornus racemosa, and Teucrium canadense

Round-fruited St John's wort is found in wet prairies and moist sites subject to disturbance.

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.

Minimize disturbance to hydrology, including soil disturbance from rutting.

Maintain and restore open habitat through selective clearing and brushing.

Survey for and control invasive plants prior to conducting timber operations, as these can be spread by vehicles and often respond vigorously to increased light. See forestry BMPs for invasive species.

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.