New York Natural Heritage Program
Creeping St. John's-wort
Hypericum adpressum Raf. ex W. Bart.
Dicots

Habitat [-]
These plants occur in saturated to flooded acidic sands and peat of coastal plain pond shores, swales, and wet meadows of the coastal plain.

Associated Ecological Communities [-]
  • Coastal plain pond shore
    The gently sloping shore of a coastal plain pond with seasonally and annually fluctuating water levels. Plants growing on the pond shore vary with water levels. In dry years when water levels are low there is often a dense growth of annual sedges, grasses, and herbs. Submerged and floating-leaved aquatic plants, such as fragrant waterlily and pondweeds, may become "stranded" on the exposed shore. In wet years when the water level is high only a few emergents and floating-leaved aquatics may be noticeable. The vegetation of this pond shore community can change dramatically from one year to the next depending on fluctuations in groundwater levels.
  • Shallow emergent marsh
    A marsh meadow community that occurs on soils that are permanently saturated and seasonally flooded. This marsh is better drained than a deep emergent marsh; water depths may range from 6 in to 3.3 ft (15 cm to 1 m) during flood stages, but the water level usually drops by mid to late summer and the soil is exposed during an average year.
  • Undetermined open mineral soil wetlands
    This subsystem includes wetlands with less than 50% canopy cover of trees. There are 11 different community types within this subsystem.

Associated Species [-]
  • Three-lobe Beggar-ticks (Bidens tripartita)
  • Blue-joint Reedgrass (Calamagrostis canadensis)
  • Common Buttonbush (Cephalanthus occidentalis)
  • Coast Pepper-bush (Clethra alnifolia)
  • Rose Coreopsis (Coreopsis rosea)
  • Toothed Sedge (Cyperus dentatus)
  • Hairy Swamp Loosestrife (Decodon verticillatus)
  • Threeway Sedge (Dulichium arundinaceum)
  • Horse-tail Spikerush (Eleocharis equisetoides)
  • Robbins Spikerush (Eleocharis robbinsii)
  • Flat-top Fragrant Goldenrod (Euthamia graminifolia)
  • Many-flowered Pennywort (Hydrocotyle umbellata)
  • Common Rush (Juncus effusus)
  • Bayonet Rush (Juncus militaris)
  • Globe-fruited False-loosestrife (Ludwigia sphaerocarpa)
  • Sessile-leaved Bugleweed (Lycopus amplectens)
  • Brownish Beakrush (Rhynchospora capitellata)
  • Tall Beaked-rush (Rhynchospora macrostachya)
  • Three-square Bulrush (Schoenoplectus pungens)
  • Smith's Bulrush (Schoenoplectus smithii)
  • Cottongrass Bulrush (Scirpus cyperinus)
  • Hardhack Spiraea (Spiraea tomentosa)
  • Highbush Blueberry (Vaccinium corymbosum)