General

• North American Native Plant Society
  www.nanps.org
• Lady Bird Johnson Wildflower Center Native Plant Guide
  www.enature.com/guides/select_lbjnative.asp

Lists (see also individual state listings below)

• Native Plant Information Sheets, Bowman's Hill Wildflower Preserve
  www.bhwp.org/native/native_plants_info_sheets.htm
• Plant Tables: You and Your Land, A Homeowner's Guide for the Potomac River Watershed, Fairfax County, VA
  www.fairfaxcounty.gov/nvswcd/youyourland/planttables.pdf 

Gardening/Landscaping with

• Landscaping with Native Plants in the Middle-Atlantic Region, Elizabeth N. duPont, 2nd edition- book available for purchase through the Brandywine Conservancy
  www.brandywinemuseumshop.org/catalog/index.cfm/ItemID/BC4DEF15-4E42-4ECF-A8B1545CEBBFCB2B/display/detail 

In Pennsylvania 

• Pennsylvania Native Plant Society
  www.pawildflower.org
• Common Trees of Pennsylvania (DCNR) (includes some non-natives)
  www.dcnr.state.pa.us/forestry/commontr/

In New Jersey

• Native Plant Society of New Jersey
  www.npsnj.org/

In Delaware

• Native Plants for Delaware Landscapes, University of Delaware:
  http://ag.udel.edu/extension/horticulture/pdf/NativePlants.pdf

Ferns

• Herbaceous Perennials: Ferns
  http://www.dcnr.state.pa.us/forestry/wildplant/ferns.aspx
• American Fern Society
  http://amerfernsoc.org/

Nurseries for Native Plants

• Local
  • New Moon Nursery (Kennett Square- wholesale- herbaceous)
    newmoonnursery.com/
  • Octoraro Native Plant Nursery (wholesale- trees and shrubs)
    www.octoraro.com/
  • Redbud Native Plant Nursery (Glen Mills- wholesale and retail- trees, shrubs, herbaceous)
    www.redbudnativeplantnursery.com/
  • Taproot Native Design (West Grove- habitat restoration)
    www.taprootnativedesign.com
  • Yellow Springs Farm (Chester Springs- retail- trees, shrubs, herbaceous)
    www.yellowspringsfarm.com/
• Mail/Internet order
  • American Chestnut Cooperators' Foundation (blight-resistant American chestnuts)
    www.accf-online.org
  • Bowman's Hill Wildflower Preserve (New Hope, PA- retail seed packets and semi-annual plant sales- woody and herbaceous)
    www.bhwp.org/seed_catalog/index.htm
  • Ernst Conservation Seeds Catalog, (Meadville, PA- retail- woody and herbaceous)
    www.ernstseed.com/
  • New England Wildflower Society (MA- retail- herbaceous)
    www.newfs.org/nursery.htm
  • Pinelands Nursery and Supply Catalog, (NJ- wholesale- woody and herbaceous)
    www.pinelandsnursery.com
  • Prairie Moon Nursery (MN- retail w/online ordering- woody and herbaceous)
    www.prairiemoon.com/
  • Prairie Nursery (WI- retail- herbaceous)
    www.prairienursery.com/
  • Shooting Star Nursery (KY- retail- woody and herbaceous)
    www.shootingstarnursery.com/index.html

Wildlife Benefits of 

• Landscaping for Wildlife, PSU Extension
  pubs.cas.psu.edu/FreePubs/pdfs/UH128.pdf
• Native Trees and Shrubs and their wildlife users, Natural Lands Trust
  www.conserveland.org/lpr/download/6736/Nativetrees.pdf
• Attracting Wildlife: Sources of Assistance, PSU Extension
  pubs.cas.psu.edu/FreePubs/pdfs/uh106.pdf
• Plants for Beneficial Insects, National Audubon Society
  www.audubon.org/bird/at_home/PlantsForBeneficialInsects.html