Classification of Vegetation Communities of Maryland: First Iteration

V. HERBACEOUS VEGETATION
V.C.2.N.a. Permanently flooded temperate or subpolar hydromorphic rooted vegetation
V.C.2.N.a.12. PODOSTEMUM CERATOPHYLLUM PERMANENTLY FLOODED HERBACEOUS ALLIANCE
Riverweed Permanently Flooded Herbaceous Alliance

Concept: Vegetation of shoals in rocky streambeds and riverbeds in mature drainage systems where the streams have cut down to rock, and the floodplain is relatively narrow; or on dams in moderately fast- to fast-flowing water. The vegetation grows attached to rocks in outcrops and stream rubble, or to dams in moderate- to fast-flowing water. This almost always is a monospecific community dominated by Podostemum ceratophyllum with no other vascular plants present; some Rhodophyta (red algae) may be present.

Comments: Vegetation of this alliance has been documented from the Sepulga River in the East Gulf Coastal Plain of Alabama. In the Interior Low Plateau of Tennessee, this vegetation is known from the upper Duck River at Manchester (Old Stone Fort State Park).

Range: This alliance is found in Alabama, Arkansas, Georgia, Kentucky, North Carolina, Oklahoma, South Carolina, Tennessee, Connecticut, Delaware, Massachusetts, Maryland, Maine, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, and Virginia.

States/Provinces: AL AR CT DE GA KY LA? MA MD ME NC NH NJ NY OK PA RI SC TN VA VT

TNC Ecoregions: 38:C, 39:C, 43:C, 44:C, 50:C, 51:C, 52:C, 53:C, 59:C, 60:C, 61:C

USFS Ecoregions: 212Fa:CCP, 212Fc:CCC, 212Fd:CCP, 212Ga:CCP, 212Gb:CCP, 221Ae:CCC, 221Af:CCC, 221Ag:CCC, 221Ah:CCP, 221Ai:CCC, 221Al:CCP, 221Am:CCC, 221Bd:CCC, 221Da:CCC, 221Db:CCP, 221Dc:CCP, 221Ha:CCC, 221Hb:CCC, 221Hc:CCC, 221He:CCC, 222Eb:CCC, 222En:CCP, 222Eo:CCP, 231Af:CCC, 232Bj:CCC, M212Bb:CCC, M212Bc:CCP, M212Bd:CCP, M221Aa:CC?, M221Ab:CC?, M221Ac:CCC, M221Ad:CC?, M221Bb:C??, M221Bd:C??, M221Be:C??, M221Bf:C??, M221Da:CC?, M221Dc:CCC, M221Dd:CCC, M222Aa:CCC, M231Aa:CCC, M231Ab:CCC, M231Ac:CCC, M231Ad:CCC

Federal Lands: USFS (Daniel Boone, Oconee?, Ouachita, Ozark, Sumter, Uwharrie)

Synonymy: Rocky Bar and Shore, in part (Schafale and Weakley 1990); Podostemum ceratophyllum herbaceous alliance (Hoagland 1998a); Shoal and Stream Bar, in part (Nelson 1986)

References: DuMond 1970, Hoagland 1998a, Nelson 1986, Schafale and Weakley 1990, Tobe et al. 1992

Authors: A.S. WEAKLEY, MP, Southeast Identifier: A.1752

Concept: This association represents essentially monospecific beds of Podostemum ceratophyllum, although some algae may also be present. This submersed vegetation forms a low mat or crust attached to rocks in moderately fast- to fast-flowing water. Typical habitat for this association in the Central Appalachians and related areas includes rocky surfaces of streambeds and riverbeds in mature drainage systems where the streams have cut down to rock and the floodplain is relatively narrow, or on dams. It tends to be associated with higher pH streams which cut through diabase, limestone or calcareous shales.

Comments: Podostemum could easily be the poster child of Piedmont rivers (B. Adams pers. comm.); it is unlikely that many aquatic plant species in the Piedmont have been hit harder. It is very sensitive to sedimentation and, accordingly, has declined greatly throughout its range and has been lost from nearly all areas it once occupied in some drainages such as the Upper Neuse Basin of North Carolina (Adams pers. comm.). This vegetation has been documented from the Sepulga River in the East Gulf Coastal Plain of Alabama, the upper Duck River at Manchester (Old Stone Fort State Park) in the Interior Low Plateau of Tennessee, the Middle Oconee River, Georgia (Nelson and Scott 1962), the Eno River and formerly many sites in the Upper Neuse River Basin in the Piedmont of North Carolina (B. Adams pers. comm.), the Savannah River, and the Mechums and South Anna rivers in Virginia (Mulholland and Lenat 1992). It is apparently rare in Arkansas, found primarily in the Arkansas River and apparently in the Ouachita River (Smith 1988b). This type may also occur in the base-rich waters of the Shenandoah River and its two forks, the James River and portions of the Roanoke River (Fleming et al. 2001). In Georgia, this type appears to be restricted to the Piedmont and is apparently absent from the northwestern part of the state (Jones and Coile 1988).

Range: This community is wide-ranging, occurring in rivers throughout the eastern and southeastern United States.

States/Provinces: AL:S?, AR:S?, CT:S?, DE:S?, GA:S?, KY:S?, LA?, MA:S?, MD:S?, ME:S?, NC:S5, NH:S?, NJ:S?, NY:S?, OK:S?, PA:S?, RI:S?, SC:S?, TN:S?, VA:S?, VT:S?

TNC Ecoregions: 38:C, 39:C, 43:C, 44:C, 50:C, 51:C, 52:C, 53:C, 59:C, 60:C, 61:C

USFS Ecoregions: 212Fa:CCP, 212Fc:CCC, 212Fd:CCP, 212Ga:CCP, 212Gb:CCP, 221Ae:CCC, 221Af:CCC, 221Ag:CCC, 221Ah:CCP, 221Ai:CCC, 221Al:CCP, 221Am:CCC, 221Bd:CCC, 221Da:CCC, 221Db:CCP, 221Dc:CCP, 221Ha:CCC, 221Hb:CCC, 221Hc:CCC, 221He:CCC, 222Eb:CCC, 222En:CCP, 222Eo:CCP, 231Af:CCC, 232Bj:CCC, M212Bb:CCC, M212Bc:CCP, M212Bd:CCP, M221Aa:CC?, M221Ab:CC?, M221Ac:CCC, M221Ad:CC?, M221Bb:C??, M221Bd:C??, M221Be:C??, M221Bf:C??, M221Da:CC?, M221Dc:CCC, M221Dd:CCC, M222Aa:CCC, M231Aa:CCC, M231Ab:CCC, M231Ac:CCC, M231Ad:CCC

Federal Lands: USFS (Daniel Boone, Oconee?, Ouachita, Ozark, Sumter, Uwharrie)

Synonymy: Open Water/Aquatic Bed Veg., Mountain Stream (Ambrose 1990a) B, Rocky Bar and Shore (Riverweed Subtype) (Schafale 1998b), River-weed shallow shore (CAP pers. comm. 1998), Mountain river (Wharton 1978)

References: Adams pers comm., Ambrose 1990a, Breden et al. 2001, CAP pers. comm. 1998, Campbell et al. 1990, Fleming et al. 2001, Hoagland 2000, Jones and Coile 1988, Mulholland and Lenat 1992, Nelson 1986, Nelson and Scott 1962, Peet et al. 2002, Schafale 1998b, Schafale and Weakley 1990, Smith 1988b, Thomas and Allen 1993, Wharton 1978

Authors: R.E. Evans, SCS Confidence: 2 Identifier: CEGL004331  

- Maryland Vegetation Classification Subset Report V.C. Hydromorphic rooted vegetation

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