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608-416-3377
Pin Oak (Quercus palustris)

Photo © Kitty Kohout
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
Identification
- 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.
Phenology
- 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
Other
- 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.
Summary Information |
State Status | SC |
Federal Status in Wisconsin | none |
State Rank | S1 |
Global Rank | G5 |
Tracked by NHI | Y |
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).
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.
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.
Other resources
Links to additional Pin Oak information
Other links related to vascular plants (all exit the DNR website)
Photos
Click to view a larger version. Please considering donating a photo to the Natural Heritage Conservation Program for educational uses. Photo use

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Photo © Kitty Kohout.

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Photo © Kitty Kohout.

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Photo © Kitty Kohout.

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Photo © Kitty Kohout.

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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