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Zigzag Bladderwort (Utricularia subulata)

Life history

Species overview

Zigzag Bladderwort (Utricularia subulata), a plant, is found near Lake Michigan in wet places between dunes, as well as in bogs or poor fens. Blooming occurs late June to August; fruiting occurs July to August. The optimal identification period for this species is August through September.

Synonyms: Setiscapella cleistogama, Setiscapella subulata, Utricularia cleistogama


  • Distinguishing characteristics: Distinguished by its small calyx (less than 2 mm long) and leaves (simple, filiform, embedded in substrate).
  • Flower characteristics: Flowers both cleistogamous and chasmogamous; fully open (chasmogamous) flowers are yellow and 2-lipped with lower lip larger than upper lip; cleistogamous flowers inconspicuous.
  • Fruit characteristics: Round capsule with 2 valves.
  • Leaf characteristics: Tiny, linear, often found on basal branches buried beneath surface.


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


  • Growth form: Forb-erect
  • Vegetative reproduction:
  • Life cycle: Annual/ Perennial
  • Comments: Associated Species: Cladium mariscoides, Scirpus americanus, Eleocharis elliptica, Lobelia kalmii, Potentilla anserina.

State status

Status and Natural Heritage Inventory documented occurrences in Wisconsin

Zigzag Bladderwort (Utricularia subulata) is on the "watch list." Watch list species have experienced, or are believed to have experienced, a statewide or range wide decline, but they are not currently tracked in the Natural Heritage Inventory (NHI) database. The watch list includes newly discovered species for which origin and rarity need to be determined, certain animals designated as Species of Greatest Conservation Need (SGCN) in the Wisconsin Wildlife Action Plan, and species that were tracked in the past but proved more abundant, widespread or less vulnerable than previously thought. Although watch list species are not actively tracked by NHI, occurrences documented during surveys are often stored by NHI, as these species could be tracked in the future if there is further evidence of their decline.

Summary Information
State Statusnone
Federal Status in Wisconsinnone
State RankSU
Global RankG5
Tracked by NHIW

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 near Lake Michigan in wet places between dunes, as well as in bogs or poor fens.
  • Soils: Sandy soils.

Natural communities

This table lists the natural communities that are associated with Zigzag Bladderwort. 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

Ecological landscapes

This table lists the ecological landscape association scores for Zigzag Bladderwort. 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

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 broadcast spraying of herbicides; use care with spot spraying.
  • 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.

Management guidance

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

  • Minimize disturbance to hydrology, including soil disturbance from rutting.
  • This species is likely sensitive to water quality. Following BMPs around streams and buffering associated drainages will reduce eutrophication and prevent water quality degradation.
  • Avoid rapid and dramatic reductions in canopy cover or basal area in wet areas to reduce risk of swamping.


Zigzag Bladderwort Photo.

Photo by Kevin Doyle, Wisconsin DNR.

Zigzag Bladderwort Photo.

Photo by Kevin Doyle, Wisconsin DNR.

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