22 September 2024.
Pennsylvania, United States
Locality: Lancaster and York Counties: outcrops along the Susquehanna River, accessed from the Historic Lock 12 parking lot off of Pennsylvania Road 372.
Coordinates: 39.8148, -76.3276
(Map it)
Elevation: 34m.
Georeference protocol: Lat/lon determined by GPS
Habitat: Wild Habitat
Environment description: Plants are growing from part-sun to full sun in crevices of the outcrops and where organic debris has accumulated in between boulders along the Susquehanna River. The sites range from nearly xeric to dry mesic, at least on the surface. Plants are generally growing 4-10 m above the normal flow of the river; however, the Holtwood Dam is less than 1 kilometer upstream and debris found trapped in the boulders indicates that there is periodic flooding, at least, in the lower zone of 4+ meters or so above normal river flow. This habitat has a diverse assemblage of deciduous trees and shrubs as well as abundant herbaceous taxa. Slope: 0 to 60 percent. Aspect: Northeast (generally). Geology: The underlying geology of this area is probably of lower Paleozoic age and characterized as the Octoraro Formation. It includes albite-chlorite schist, phyllite, some hornblende gneiss, and granitized members. Soils: The area where this species occurs is right on the edge of two soil zones that transition from the river’s edge to mesic conditions upslope. The first is generally referred to as Rock Outcrop. This terrestrial matrix in which plants grow is largely exposed underlying rock geology with accumulated outwash, rock decomposition, and organic debris buildup. The second is Mt. Airy (80%) and Manor (20%) Series soils, 25 to 60 percent slopes, extremely stony (MRF). (Source: California Soil Resource Lab/NRCS Official Soil Series Descriptions). EPA Ecoregion (Level III): Northern Piedmont (64). EPA Ecoregion (Level IV): Piedmont Uplands (64c).
Number of plants sampled: 15
Associated species: Baptisia tinctoria; Fagus grandifolia; Alnus serrulata; Collinsonia canadensis; Amorpha fruticosa; Toxicodendron radicans; Schizachyrium scoparium; Solidago bicolor; Solidago racemosa; Vaccinium angustifolium; Acer rubrum; Acer saccharinum; Aronia melanocarpa; Betula nigra; Vaccinium stamineum; Vaccinium corymbosum; Hypericum prolificum; Ionactis linariifolia; Rubus sp.; Fraxinus pennsylvanica; Viburnum dentatum; Quercus montana; Nyssa sylvatica; Malus sp.; Platanus occidentalis; Symphyotrichum sp.; Ageratina altissima; Chionanthus virginicus; Phlox subulata; Lonicera japonica; Rhododendron arborescens; Hamamelis virginiana; Physocarpus opulifolius; Crataegus sp.; Kalmia latifolia; Rhododendron periclymenoides; Sedum sarmentosum; Parthenocissus quinquefolia; Prunus serotina; Diospyros virginiana; Amelanchier sp.; Cornus amomum [listed as Swida amomum]; Heuchera americana; Asplenium platyneuron; Eutrochium sp.; Carya glabra; Lindera benzoin; Asimina triloba; Ulmus americana; Viburnum prunifolium; Lonicera maackii; Uvularia sessilifolia; Clematis virginiana; Solidago juncea; Vitis sp.; Ilex verticillata; Carya cordiformis; Reynoutria japonica; Polystichum acrostichoides; Athyrium filix-femina; Eurybia divaricata; Tilia americana; Betula lenta; Quercus rubra; Rubus phoenicolasius; Liriodendron tulipifera; Veronicastrum virginicum; Hydrangea arborescens; Sedum ternatum; Aquilegia canadensis; Thalictrum pubescens; Vaccinium pallidum; Pycnanthemum tenuifolium; Ambrosia artemisifolia; Cystopteris sp.; Carpinus caroliniana; Chelone glabra; Asplenium trichomanes; Onoclea sensibilis; Rhus copallinum.
Comment: Plants are deciduous, multi-stemmed low-growing shrubs with an irregular spreading habit reaching 30-60 cm tall and 0.5 m wide. Stems are generally glabrous and range from green with reddish tinge to yellowish-brown on 1–3-year-old stems; internodal prickles present or absent and are sparse, straight, and slender. Leaves are compound, alternate and generally glabrous at this time of year. Leaves have 5-7 leaflets with serrate leaf margins; stipule surfaces are glabrous with stipitate glands along the margins. Fruits are red, globose to depressed-globose, and 9-14 mm wide x 6-9 mm long. The sepals, where still present, are lanceolate, spreading, and densely stipitate glandular; however, the sepals are absent on many fruits. This species is scattered, but relatively common on the boulder outcrops and woodland edge along this portion of the Susquehanna River. Seed collected from 15 plants; approximately 200 fruits collected. NOTE: According to The Plants of Pennsylvania, Rosa carolina can be difficult to differentiate from Rosa virginiana due to the occurrence of numerous intermediates in this area where their ranges overlap.
Collector(s):