Habitat
Ilex collina occurs in high elevation oligotrophic wetlands along streams, and streamheads from 2120-4815 ft. It often occurs in association with Tsuga canadensis, Betula lenta, Ilex montana, Picea rubens, and Rhododendron maximum.
Ecology
North Carolina -- Ilex collina occurs in tall shrub thickets and has been noted on one western slope in a creek valley. Plants associated with this species include Aronia sp., Carex trisperma, Epilobium leptophyllum, Kalmia sp., Lilium grayi, Lonicera canadensis, L. dioica, Rhododendron sp., Salix sp., Saxifraga pensylvanica, and Vaccinium sp. (NCNHP, 1996).
Virginia -- This species occurs along bog borders, beaver ponds, mucky ground, hydric peat, and oligotrophic saturated wetlands. It grows in sun and has been noted on a 3% slope with an eastern aspect. The elevations for these occurrences ranged from 3000-4815 ft. The generalized communities have been described as sphagnum/sedge bogs and open shrub near hardwood forest and including some spruce. It is associated with the following plants: Acer rubrum, Betula alleghaniensis, B. lenta, Glyceria melicaria, Osmunda cinnamomea, Picea rubens, Pinus strobus, Rhododendron arborescens, R. maximum, Tsuga canadensis, and Viburnum cassinoides (VANHP, 1995).
West Virginia -- This species in noted in wetland areas (bog, marsh, and swamp), river edges, high energy and/or scoured (rock sand and cobble) riverbanks, sandstone soils, and northern hardwoods. Elevations for occurrences ranged from 2150 to 4500 ft. Associated plant species included Acer rubrum, Aconitum uncinatum, Agrostis perennans, Betula alleghaniensis, B. lenta, Brachyelytrum erectum, Calamagrostis canadensis, Cicuta maculata, Clintonia borealis, Dennstaedtia punctilobula, Fagus grandifolia, Galium obtusum, Hamamelis virginiana, Ilex montana, Kalmia sp., Liriodendron tulipifera, Maianthemum canadense, Physocarpus opulifolius, Picea rubens, Quercus rubra, Rhododendron aborescens, Solidago graminifolia, Thalictrum polygamum, and Tsuga canadensis (WVNHP, 1996).