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Pin Oak (Quercus palustris)

Life history

Species overview

Pin Oak (Quercus palustris), a Wisconsin Special Concern plant, is found in southern floodplain forests. Blooming occurs throughout May; fruiting occurs late July through early September. The optimal identification period for this species is late May through late September.

Synonyms: None


  • Distinguishing characteristics: Leaves appear similar to Q. elllipsoidalis (northern pin oak) and Q. coccinea (scarlet oak), but Q. palustris can be distinguished from these species by having a shallower acorn cup, covering only about 1/4 of the nut. Also, Q. palustris is found in wet lowlands as oppose to well-drained uplands.
  • Flower characteristics: Male catkins hairy, 5 to 10 cm; female flowers with wooly hairs; stigmas red.
  • Fruit characteristics: Acorn 1 to 2.5 cm wide; acorn cap saucer-shaped with very small scales that are covered with tiny hairs, covers 1/4 to 1/3 of the nut which is 10 to 14 mm wide.
  • Leaf characteristics: Shiny, paler on the underside, often tapering to a point at the base, wrapping around the petiole slightly, 2 to 3 pairs of toothed lobes, each lobe much longer than the center part of the leaf is wide.


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


  • Growth form: Tree
  • Vegetative reproduction:
  • Life cycle: Perennial
  • Comments: Associated Species: Acer saccharinum, Ulmus americana, Betula nigra, Quercus bicolor, Salix nigra, Leersia lenticularis, Carex muskingumensis.

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 Pin Oak (Quercus palustris). 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 Quercus palustris 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 southern floodplain forests.
  • Soils: Streambottom or major wetland soils.

Natural communities

This table lists the natural communities that are associated with Pin Oak. 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
Floodplain Forest 3

Ecological landscapes

This table lists the ecological landscape association scores for Pin Oak. 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 Coulee and Ridges 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 site preparation that heavily disturbs herbaceous ground layer and soil; these include bulldozing and furrowing, as well as grubbing and stump removal.
  • 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

  • Minimize disturbance to hydrology, including soil disturbance from rutting.
  • Avoid rapid and dramatic reductions in canopy cover or basal area in wet areas to reduce risk of swamping.


Pin Oak Photo.

Photo © Kitty Kohout.

Pin Oak Photo.

Photo © Kitty Kohout.

Pin Oak Photo.

Photo © Kitty Kohout.

Pin Oak Photo.

Photo © Kitty Kohout.

Pin Oak Photo.

Quercus palustris

Photo © Suzan Campbell.

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