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- For information on Wisconsin's rare plants, contact:
- Kevin Doyle
608-416-3377
Sand Reedgrass (Calamovilfa longifolia var. magna)

Photo © Hugh Iltis
Life history
Species overview
Sand Reedgrass (Calamovilfa longifolia var. magna), a Wisconsin Threatened plant, is found on Lake Michigan sand dunes. Blooming occurs early July through late September; fruiting occurs early August through late September. The optimal identification period for this species is early July through late September.
Synonyms: None
Identification
- Distinguishing characteristics: Large grass primarily of dunes with broad, open, spreading panicle (distinguishing it from the more tightly contracted panicle of C. longifolia var. longifolia) and numerous callus hairs on the lemma; leaves up to 12 mm wide with villous sheaths.
- Flower characteristics: Panicle 15 to 35 cm long, open, and spreading; floral spike 15 to 70 cm long, 1.3 to 6 times as long as wide, often broader than in other similar species.
- Fruit characteristics: Spikelets pale, 6 to 7 mm long; glumes acuminate, the first about 2 mm shorter than the second; lemma somewhat shorter than the second glume, glabrous, the callus hairs copious, more than half as long as the lemma.
- Leaf characteristics: Leaf blade up to 60 cm long and 12 mm wide; base of leaf sheaths wraps down around the stem for up to 15 cm and is densely covered in small hairs; sheaths usually more or less appressed-villous, especially near the summit; blades firm, elongate, flat or soon involute, tapering to a long fine point.
Phenology
- Blooming phenology: early July through late September
- Fruiting phenology: early August through late September
- Optimum time to identify: The optimal identification period for this species is early July through late September
Other
- Growth form: Graminoid
- Vegetative reproduction: Rhizomatous
- Life cycle: Perennial
- Comments: Associated Species: Ammophila breviligulata, Elymus lanceolatus ssp. psammophilus, Artemisia campestris, Juniperus horizontalis, Lathyrus japonicus.
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 Sand Reedgrass
(Calamovilfa longifolia var. magna). 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 | THR |
Federal Status in Wisconsin | none |
State Rank | S2 |
Global Rank | G5T3T5 |
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 on Lake Michigan sand dunes.
- Soils: Sandy soils.
Natural communities
This table lists the natural communities that are associated with Sand Reedgrass. 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 Sand Reedgrass. 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 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
- Avoid disturbance to shorelines and the forest-beach interface.
- Avoid any activities which destabilize the dune, including the use of off-road vehicles, removal of native vegetation and pedestrian recreational overuse.
Other resources
Links to additional Sand Reedgrass 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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Calamovilfa longifolia var. magna
Photo by Kevin Doyle, Wisconsin DNR.

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Calamovilfa longifolia var. magna
Photo by Kevin Doyle, Wisconsin DNR.

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Calamovilfa longifolia var. magna
Photo by Kevin Doyle, Wisconsin DNR.

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Photo © Hugh Iltis, Wisconsin State Herbarium
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