Columbia subject headings:
English ivy.
Iris pseudacorus.
Japanese honeysuckle.
Plant ecology--Washington (D.C.)
Plant introduction--Washington (D.C.)
Theodore Roosevelt Island (Washington, D.C.)
Weeds--Washington (D.C.)
Harvard subject headings:
Princeton subject headings:
Botany--Washington (D.C.)--Ecology.
English ivy.
Iris pseudacorus.
Japanese honeysuckle.
Plant introduction--Washington (D.C.).
Theodore Roosevelt Island (Washington, D.C.)
Weeds--Washington (D.C.).