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Louisiana Broomrape (Orobanche ludoviciana)

Life history

Species overview

Louisiana Broomrape (Orobanche ludoviciana), a Wisconsin Endangered plant, is found in sandy areas, including dry prairies, barrens and creek bottoms. Blooming occurs late August through early September; fruiting occurs throughout September. The optimal identification period for this species is late August through early September.

Synonyms: Orobanche ludoviciana var. arenosa, var. genuina, var. ludoviciana; Myzorrhiza ludoviciana; Orobanche multiflora var arenosa; Aphyllon arenosum, Conopholis ludoviciana


  • Distinguishing characteristics: Calyx 5-lobed, the lobes less than equal, linear and well developed.
  • Flower characteristics: Spikes many-flowered, dense, forming 33 to 67% of the shoot; flowers mostly sessile or the lower on erect pedicels to 15 mm; calyx subtended by 1 or 2 bractlets, as well as by a bract, 2-lipped, the upper lip with a single lobe, the lower with 4, calyx lobes linear, 8 to 12 mm; corolla often purplish, 1.5 to 2.5 cm.
  • Fruit characteristics: 2-valved capsule, many seeded.
  • Leaf characteristics: Reduced to scales, many, appressed.


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


  • Growth form: Forb-erect
  • Vegetative reproduction:
  • Life cycle: Annual
  • Comments: Associated Species: Heterotheca villosa, Sporobolus cryptandrus, Cenchrus longispinus. Root parasite.

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 Louisiana Broomrape (Orobanche ludoviciana). 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 Orobanche ludoviciana in the Natural Heritage Inventory Database as of July 2015.

Summary Information
State StatusEND
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 sandy areas, including dry prairies, barrens and creek bottoms.
  • Soils: Sandy soils.

Natural communities

This table lists the natural communities that are associated with Louisiana Broomrape. 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
Sand Prairie 3

Ecological landscapes

This table lists the ecological landscape association scores for Louisiana Broomrape. The scores (3=High, 2=Moderate, 1=Low, 0=None) also correspond to the map.

Map of the Ecological Landscapes of Wisconsin.

Ecological landscape score
Western Prairie 3

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 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

  • Prescribed burns and/or brushing may be beneficial (dependent on local site conditions).
  • Maintain and restore open habitat through selective clearing and brushing.


Louisiana Broomrape Photo.

Photo © Emmet Judziewicz.

Louisiana Broomrape Photo.

Photo © Emmet Judziewicz.

Louisiana Broomrape Photo.

Photo © Emmet Judziewicz.

Louisiana Broomrape Photo.

The flowers of Louisiana broomrape are arranged in a dense spike. WI's other two Orobanche spp have either a single flower or a few not as densely clustered flowers.

Photo © Dan Carter.

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