Common (Translated Scientific) Name: Pale Touch-me-not - Dwarf Scouring-rush - Fen Grass-of-Parnassus Seep Alliance
Colloquial Name: Great Lakes Clay Seep
Hierarchy Level: Alliance
Type Concept: This vegetation is found in the northern regions of the Great Lakes in the United States. Stands occur on toeslopes, where constant seepage creates saturated clay soils. Substrate is neither mucky not peaty. Stands are often shaded (up to 90% cover) by adjacent forest types, including Tsuga canadensis- and Acer saccharum-dominated stands. Trees rarely occur in the seepage zone itself, which can be as much as 30 m wide. Characteristic plants include Equisetum scirpoides (often dominant) and Impatiens pallida.
Diagnostic Characteristics: This alliance includes apparently distinctive vegetation of clay-based seepage areas in the northern regions of the Great Lakes. It is distinguished on floristic, landform, and biogeographic criteria.
Rationale for Nominal Species or Physiognomic Features:
Classification Comments: Old alliance Clay Slopes Sparsely Vegetated Alliance (A.1871) and its single association are assigned to this new alliance, due to its range and distinctive flora. There are apparently no similar types. Perhaps there is similar vegetation in Canada. Its group placement should be reviewed. The concept is based on field sites observed by E. Epstein in Wisconsin.
Similar NVC Types:
Diphylleia cymosa - Saxifraga micranthidifolia Seep Alliance, note:
Carex atlantica - Solidago patula - Parnassia asarifolia Seep Alliance, note:
Carex gynandra - Glyceria melicaria - Glyceria striata Seep Alliance, note:
Lyonia ligustrina - Photinia pyrifolia / Drosera rotundifolia Seep Alliance, note:
Sanguisorba canadensis - Parnassia grandifolia Seep Alliance, note:
Physiognomy and Structure: Stands are often shaded (up to 90% cover) by adjacent forest types, including Tsuga canadensis- and Acer saccharum-dominated stands. Trees rarely occur in the seepage zone itself, which can be as much as 30 m wide.
Floristics: Characteristic plants in stands of this alliance include Equisetum scirpoides (often dominant) and Impatiens pallida. Other species in northern Wisconsin include Cypripedium reginae, Cypripedium parviflorum, Equisetum arvense and, rarely, Parnassia palustris and Parnassia glauca. In southeastern Wisconsin, common species include Gentianopsis virgata (= Gentianopsis procera), Oligoneuron ohioense (= Solidago ohioensis), and Triantha glutinosa (= Tofieldia glutinosa). Other fen plants may also occur. Epipactis helleborine is a common exotic orchid.
Dynamics: Unstable bluffs generally support a more "weedy" flora, resembling that of the surrounding forest.
Geographic Range: This alliance is found in the northern regions of the Great Lakes in the United States. There may be similar vegetation in Canada.
Nations: CA?, US
States/Provinces: MI?, WI
|US Forest Service Ecoregions (1994/1995)|
Laurentian Mixed Forest Province
Confident or certain
Southern Superior Uplands Section
Confident or certain
Concept Author(s): E. Epstein, in Faber-Langendoen et al. (2013)
Author of Description: D. Faber-Langendoen
Version Date: 18Dec2014