These plants from the eastern regions of the US and around the globe will co-mingle happily with native plants. They are showy but consistent with the look of native plant communities and will not invade your woodlands or gobble up everything in their path.
Follow the links to descriptions of specific cultivars from the Missouri Botanical Garden Plant Finder or Wikipedia.
Groundcovers for Shade
Bishop’s hat Epimedium spp.
Japanese painted fern Athyrium niponicum
Lenten rose Helleborus spp.
Lily turf Liriope muscari (caution: considered invasive in southern US)
Plantain lily Hosta spp.
Tassel fern Polystichum polyblepharum
Ornamental Shrubs
Beautyberry Callicarpa dichotoma
Beautybush Kolkwitzia amabilis
Carolina allspice Calycanthus floridus
Cotoneaster Cotoneaster spp.
Fothergilla cultivars Fothergilla
Lilac cultivars Syringa meyeri Syringa pubescens
Ninebark cultivars Physocarpus opulifolius (the species is native to Indiana)
Rose Rosa floribunda Knockout Series
Smokebush Cotinus coggygria Cotinus obovatus
Virginia sweetspire cultivars Itea virginica (the species is native to Indiana, but quite rare)
Weigela cultivars Weigela florida
Evergreens
Arborvitae Thuja spp. (T. occidentalis is native to Indiana)
Boxwood Buxus spp.
False cypress Chamaecyparis
Yew Taxus spp. (T. canadensis is native to Indiana)
Juniper Juniperus spp. (J. communis and J. virginiana are native to Indiana)
Small Trees
Fringe tree Chionanthus virginicus
Japanese lilac Syringa reticulata
Japaneses maple Acer palmatum spp.
Seven sons flower Heptacodium miconioides
Virginia sweetspire lends brilliant fall color