Blunt-lobe Grape-fern (Sceptridium oneidense)

Life history

Species overview

Blunt-lobe Grape-fern (Sceptridium oneidense), a Wisconsin Special Concern plant, is found in moist, often acid depressions in damp open forests. The optimal identification period for this species is late June through late September.

Synonyms: Botrychium dissectum f. oneidense, Botrychium dissectum var. oneidense, Botrychium multifidum var. oneidense, Botrychium obliquum var. oneidense, Botrychium ternatum var. oneidense

Identification

• Distinguishing characteristics: Fronds broadly triangular, 2 to 4 times pinnate with shallowly lobed, ovate pinnae (broader than the lanceolate pinnae of B. dissectum); terminal 1/2 to 1/4 of pinnae usually undivided, though may be lobed (unlike the more dissected blades of B. multifidum and B. rugulosum). Fronds produced in spring and lasting until following spring, overwintering as a leathery green blade (B. dissectum bronze in color over winter).
• Flower characteristics:
• Fruit characteristics: Fertile portion an erect spike 14 to 38 cm long and slightly to many times longer than the sterile portion, pinnately branched at its apex, each branch and brachlet bearing 2 rows of sporangia not or only slightly embedded in the branch.
• Leaf characteristics: Fronds broadly triangular, 8 to 19 cm long x 6 to 15 cm wide, 2 to 4 times pinnate with coarse, entire to shallowly lobed, ovate pinnae. Terminal 1/2 to 1/4 of pinnae usually undivided, though may be lobed; fronds produced in spring and lasting until following spring, overwintering as a leathery green blade.

Phenology

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

Other

• Growth form: Fern
• Vegetative reproduction: Rhizomatous
• Life cycle: Perennial
• Comments: Associated Species: Acer rubrum, A. saccharum, Tilia americana, Rumex acetosella.

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 Blunt-lobe Grape-fern (Sceptridium oneidense). 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.

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 moist, often acid depressions in damp open forests.
• Soils: Rich, moist soils.

Natural communities

This table lists the natural communities that are associated with Blunt-lobe Grape-fern. 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 Blunt-lobe Grape-fern. 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 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.
• Avoid site preparation that heavily disturbs herbaceous ground layer and soil; these include bulldozing and furrowing, as well as grubbing and stump removal.
• Avoid direct disturbance to sensitive microsites such as seeps, cliffs, and moss-covered boulders.

Management guidance

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

• This species has been found in second-growth forests, which makes understanding its tolerance of disturbance difficult. However, due to the long disturbance-free periods usually seen in mesic forests, it is likely that dramatic reductions in canopy cover will result in overly dry ground conditions and an influx of new plant species that will outcompete B. oneidense in the modified habitat. Management which minimizes changes to soil moisture and overall groundcover should be pursued.
• Maintain high forest canopy cover; this species requires shaded habitat conditions.
• Maintain thick duff layer if possible; minimize spread of invasive species including earthworms.
• Minimize disturbance to hydrology, including soil disturbance from rutting.

Other resources

Links to additional Blunt-lobe Grape-fern information

Other links related to vascular plants (all exit the DNR website)

• Wisconsin Flora
• NatureServe Explorer
• Atlas of Wisconsin Prairie and Savanna Flora - Wisconsin State Herbarium
• USDA - NRCS Plants Database
• USGS Midwestern Wetland Flora - field office guide to plant species
• eFloras
• Cofrin Center for Biodiversity Herbarium
• Intermountain Herbarium Grasses of North America
• Orchids of Wisconsin

Photos

Click to view a larger version. Please considering donating a photo to the Natural Heritage Conservation Program for educational uses. Photo use