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Shrubby St. John's-wort (Hypericum prolificum)

Life history

Species overview

Shrubby St. John's-wort (Hypericum prolificum), a Wisconsin Special Concern plant, is found in prairies, swamps, cliffs and woods. Blooming occurs Mid July through September; fruiting occurs late September through early November. The optimal identification period for this species is Mid July through September.

Synonyms: Ascyrum spathulatum, Hypericum spathulatum


  • Distinguishing characteristics: Distinguished from other Hypericums by having 3 styles, which are united at base and remain as a single beak on capsule until maturity.
  • Flower characteristics: Flowers yellow, 5-parted, 7 to 10 mm long, arranged in a terminal cyme.
  • Fruit characteristics: Capsule 7 to 14 mm with 3 cells or compartments.
  • Leaf characteristics: Opposite, linear to oblong, 3 to 6 cm with short petiole.


  • Blooming phenology: Mid July through September
  • Fruiting phenology: late September through early November
  • Optimum time to identify: The optimal identification period for this species is Mid July through September


  • Growth form: Shrub
  • Vegetative reproduction:
  • Life cycle: Perennial
  • Comments: Associated Species: Acer saccharum, Tilia americana, Quercus spp., Prunus serotina, Fragaria virginiana, Silphium spp., Toxicodendron radicans.

State status

Status and Natural Heritage Inventory documented occurrences in Wisconsin

The table below provides information about the protected status - state and federal - and the rank (S and G Ranks) for Shrubby St. John's-wort (Hypericum prolificum). See the Working List Key for more information about abbreviations. Counties shaded blue have documented occurrences for this species in the Wisconsin Natural Heritage Inventory database. The map is provided as a general reference of where this species has been found to date and is not meant as a range map.

Documented locations of Hypericum prolificum in the Natural Heritage Inventory Database as of July 2015.

Summary Information
State StatusSC
Federal Status in Wisconsinnone
State RankS1
Global RankG5
Tracked by NHIY

Habitats and landscapes

The Natural Heritage Inventory has developed scores indicating the degree to which each of Wisconsin's rare plant species is associated with a particular natural community or ecological landscape. This information is similar to that found in the Wildlife Action Plan for animals. As this is a work in progress, we welcome your suggestions and feedback.

General habitat information

  • Habitat description: Found in prairies, swamps, cliffs and woods.
  • Soils: Sandy soils.

Natural communities

This table lists the natural communities that are associated with Shrubby St. John's-wort. Scores for natural community associations are: "significant" association (score=3), "moderate association" (score=2) or the species can be present but is only weakly associated with the community (score=1).

Natural communities score
Oak Woodland 2
Dry Prairie 2
Dry-mesic Prairie 2

Ecological landscapes

This table lists the ecological landscape association scores for Shrubby St. John's-wort. The scores (3=High, 2=Moderate, 1=Low, 0=None) also correspond to the map.

Map of the Ecological Landscapes of Wisconsin.

Species guidance

The Endangered Resources Program has developed avoidance measures and management guidelines for plants on the Natural Heritage Working List. These are a work in progress, and we welcome your suggestions and feedback. Sources used in developing this information can be found here.

Avoidance measures

These are specific actions designed to avoid "take" (mortality) of this species.

  • 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 in open sandy areas dominated by native grasses.
  • Avoid broadcast spraying of herbicides; use care with spot spraying.

Management guidance

Management guidelines are additional considerations that may help maintain or enhance habitat for this species

  • 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.
  • Prescribed burns and/or brushing may be beneficial (dependent on local site conditions).


Shrubby St. John's-wort Photo.

Photo © Leslie J. Mehrhoff,

Shrubby St. John's-wort Photo.

Photo © Leslie J. Mehrhoff,

Shrubby St. John's-wort Photo.

Photo © Leslie J. Mehrhoff,

Support for Wisconsin's rare plant information has been provided by the Division of Forestry, the Endangered Resources Fund and the Wisconsin Rare Plant Preservation Fund. To donate, visit the Natural Resources Foundation of Wisconsin [exit DNR].

Last revised: Wednesday, May 05, 2021
Southwest Savanna Southern Lake Michigan Coastal Western Coulees and Ridges Southeast Glacial Plains Central Sand Hills Central Lake Michigan Coastal Central Sand Plains Northern Lake Michigan Coastal Northern Lake Michigan Coastal Northeast Sands Western Prairie North Central Forest Northern Highlands Northwest Lowlands Northwest Sands Northwest Lowlands Superior Coastal Plains Forest Transition