willow | Southwestern United States | Willow | Southwestern Front | Willow Grove, Pennsylvania | University of Texas Southwestern Medical Center | Asian Paradise Flycatcher | Willow Rosenberg | Willow Grove | Southwestern University | Southwestern Baptist Theological Seminary | Willow Springs | St. Louis Southwestern Railway | Southwestern University (Philippines) | southwestern United States | Southwestern College | Flint Southwestern Academy | European Pied Flycatcher | El Paso and Southwestern Railroad | Willow Creek Community Church | Willow Brook | Southwestern New Mexico | Southwestern Front (Soviet Union) | Southwestern Bell | Ochre-faced Tody-Flycatcher | Collared Flycatcher | Asian Brown Flycatcher | Willow Valley Township, St. Louis County, Minnesota | Willow Valley Township | Willow Smith |
Pollution and reduction of rivers are threatening specific plants and animals including Fremont cottonwood (Populus fremontii) and Goodding's willow (Salix gooddingii), the threatened Gila trout (Oncorhynchus gilae), the endangered Southwestern Willow Flycatcher (Empidonax traillii extimus).