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A3390 Carex lurida - Carex interior - Parnassia grandifolia Southern Interior Seepage Fen Alliance

Type Concept Sentence: These circumneutral herbaceous seepage fens are found in the central and southeastern United States, including Arkansas and Missouri (Ozarks), as well as Kentucky and Tennessee (Interior Low Plateau).


Common (Translated Scientific) Name: Shallow Sedge - Inland Sedge - Largeleaf Grass-of-Parnassus Southern Interior Seepage Fen Alliance

Colloquial Name: Southern Interior Circumneutral Seepage Fen

Hierarchy Level:  Alliance

Type Concept: These circumneutral herbaceous seepage fens are dominated by hydrophytic plants, particularly graminoids, although shrubs are often found scattered or in thickets. Herbaceous cover is high except in areas of marly ooze. Abundant herbaceous species in Ozark examples include Carex interior, Carex leptalea, Carex lurida, Impatiens capensis, Lysimachia quadriflora, Oxypolis rigidior, Rhynchospora capillacea, and Thelypteris palustris. Shrubs include Alnus serrulata, Cornus amomum, Physocarpus opulifolius, Salix caroliniana, and Salix humilis. More elevated areas dominated by perennial grasses ("prairie-like fens") include Andropogon gerardii, Castilleja coccinea, Helianthus mollis, Panicum virgatum, Rudbeckia fulgida var. umbrosa, Silphium integrifolium, Silphium terebinthinaceum, Sorghastrum nutans, and Veronicastrum virginicum. Kentucky and middle Tennessee examples from the Interior Low Plateau contain Cardamine bulbosa, Carex atlantica ssp. atlantica and Carex atlantica ssp. capillacea (instead of Carex interior), Carex leptalea ssp. harperi, Carex lurida, Impatiens capensis, Juncus brachycephalus, Juncus coriaceus, Juncus effusus, Lobelia puberula, Lobelia cardinalis, Oxypolis rigidior, Parnassia grandifolia, Phlox glaberrima, Rudbeckia fulgida var. speciosa (in the Kentucky occurrence), Rudbeckia fulgida var. umbrosa (in Tennessee occurrences), Rhynchospora capitellata, Solidago patula var. patula, and Thelypteris palustris var. pubescens. Trees are sometimes present but never common. Examples of this alliance are found in the central and southeastern United States, including Arkansas and Missouri (Ozarks), and Kentucky and Tennessee (Interior Low Plateau).

Diagnostic Characteristics: Ozark and Interior circumneutral herbaceous seepage fens dominated by Carex lurida, Carex interior, and Parnassia grandifolia.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: No Data Available

Similar NVC Types: No Data Available
note: No Data Available

Physiognomy and Structure: This is a mixed grass or sedge fen, present as a complex of zoned vegetation dominated by hydrophytic plants, particularly graminoids, although shrubs are often found scattered or in thickets. Trees are sometimes present but never common. In Missouri, several zones or types of vegetation are recognized: (1) saturated areas dominated by tussock sedges such as Carex interior and Carex lurida; (2) deep muck saturated areas, dominated by those same sedges and by Carex hystericina, Carex suberecta, and the shrub Alnus serrulata; (3) marly ooze areas dominated by Carex leptalea, Rhynchospora capillacea, and Scleria verticillata; and (4) drier areas or margins dominated by Andropogon gerardii, Parnassia grandifolia, and Rudbeckia fulgida var. umbrosa.

Floristics: These circumneutral herbaceous seepage fens are dominated by hydrophytic plants, particularly graminoids, although shrubs are often found scattered or in thickets. Herbaceous cover is high except in areas of marly ooze. Abundant herbaceous species in Ozark examples include Carex interior, Carex leptalea, Carex lurida, Impatiens capensis, Lysimachia quadriflora, Oxypolis rigidior, and Rhynchospora capillacea. Shrubs include Alnus serrulata, Cornus amomum, Physocarpus opulifolius, Salix caroliniana, and Salix humilis. In addition to the ones mentioned above, other herbaceous species present in most Missouri examples include Carex hystericina, Castilleja coccinea, Clinopodium arkansanum (= Calamintha arkansana), Fuirena simplex, Helenium autumnale, Lobelia siphilitica, Lysimachia quadriflora, Menyanthes trifoliata, Packera aurea (= Senecio aureus), Oligoneuron rigidum var. rigidum (= Solidago rigida ssp. rigida), Pedicularis lanceolata, Physostegia virginiana, Pogonia ophioglossoides, Pycnanthemum virginianum, Schoenoplectus americanus (= Scirpus americanus), Scirpus atrovirens, Scirpus lineatus, and Selaginella apoda. Deep muck fens may also contain Cardamine bulbosa, Carex granularis, Lysimachia quadriflora, Oxypolis rigidior, Pedicularis lanceolata, Physocarpus opulifolius, Rudbeckia fulgida var. umbrosa, Selaginella eclipes, Thelypteris palustris var. pubescens, and Viola cucullata (Nelson 1985, T. Nigh pers. comm. 1996). More elevated areas dominated by perennial grasses ("prairie-like fens") include Andropogon gerardii, Castilleja coccinea, Helianthus mollis, Panicum virgatum, Rudbeckia fulgida var. umbrosa, Silphium integrifolium, Silphium terebinthinaceum, Sorghastrum nutans, and Veronicastrum virginicum. Kentucky and middle Tennessee examples from the Interior Low Plateau contain Cardamine bulbosa, Carex atlantica ssp. atlantica and Carex atlantica ssp. capillacea (instead of Carex interior), Carex leptalea ssp. harperi, Carex lurida, Impatiens capensis, Juncus brachycephalus, Juncus coriaceus, Juncus effusus, Lobelia puberula, Lobelia cardinalis, Oxypolis rigidior, Parnassia grandifolia, Phlox glaberrima, Rudbeckia fulgida var. speciosa (in the Kentucky occurrence), Rudbeckia fulgida var. umbrosa (in Tennessee occurrences), Rhynchospora capitellata, Scirpus atrovirens, Scirpus cyperinus, Solidago patula var. patula, and Thelypteris palustris var. pubescens. An adjoining shrub zone is usually present, and woody species may invade the fen, including Acer rubrum, Alnus serrulata, Cornus amomum, Salix caroliniana, and Salix humilis. Some of these middle Tennessee examples provide habitat for the globally rare Xyris tennesseensis.

Dynamics:  Periodic fire may have played a role in the dynamics of this vegetation, but this is not clearly understood. These fires are likely in some of the larger fens, particularly areas dominated by perennial grasses ("prairie fens"). Alnus serrulata may invade examples of this association in the absence of fire and other disturbance. The saturated conditions of the sites, with shallow soils over bedrock on slopes, leads to some natural tree-fall, keeping some stands open, even in the absence of fire.

Environmental Description:  Examples occur on the sideslopes or toeslopes of hills in narrow valleys, bases of bluffs or cliffs, rock ledges, and valley terraces, where the soil or substrate is saturated by calcareous groundwater seepage, usually associated with streams. These sites have low to moderate slopes (5-45°) and may be of any aspect. Calcareous groundwater saturates the soils for at least part of the growing season, but they may become somewhat drier for part of the year (Nelson 1985). The soil conditions are the result of the underlying substrate and vegetation. In this fen community, the soil moisture gradient ranges from moist to wet with seasonal fluctuations. The groundwater is calcareous. The soils are usually mucky peats but can be mineral, with pH above 6.5, and varies from very shallow (0-40 cm) to deep (>100 cm), depending on natural disturbance and slope. The parent material is a mixture of gravel and dolomite, gravelly alluvium, or colluvium with fragments of deeply weathered bedrock present. The soils are typically shallow to deep (40-100+ cm) but can be very shallow (<40 cm). The bedrock strata are exposed, especially in hanging fens where the slope is greater than 35°. In Arkansas, occurrences are 0.5- to 1-acre areas along streams with exposed cliffline and seepage.

Geographic Range: This alliance is found in the Ozarks and Interior Low Plateau regions in Arkansas, Kentucky, Missouri, Ohio, and Tennessee, in the midwestern and southeastern United States.

Nations: US

States/Provinces:  AR, KY, MO, OH, TN




Confidence Level: Low

Confidence Level Comments: No Data Available

Grank: GNR

Greasons: No Data Available


Concept Lineage: This alliance accommodates the Ozark-Interior part of A.1452 (3/6 associations).

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available

Synonomy: = Arkansas Streamside seep-fan; sedge-shrub fen (Richardson and Gibbons 1993)
>< IIE1b. Calcareous Fen Complex (Allard 1990)
? P5B2cI1a. Parnassia grandifolia-Carex lurida (Foti et al. 1994)

Concept Author(s): M. Pyne, in Faber-Langendoen et al. (2013)

Author of Description: M. Pyne

Acknowledgements: We have incorporated significant descriptive information previously compiled by S. Orzell, P. Nelson and D. Faber-Langendoen.

Version Date: 03-14-14

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