Science magazines
- Pyne's Ground-plum
- Quino Checkerspot Butterfly
- Railroad Valley Springfish
- Razorback Sucker
- Red Hills Salamander
- Red Hills Vervain
- Red Wolf
- Red-cockaded Woodpecker
- Relict Darter
- Relict Trillium
- Remya Kauaiensis
- Remya Montgomeryi
- Ring Pink Mussel
- Ringed Map Turtle
- Rio Grande Silvery Minnow
- Riparian Brush Rabbit
- Riverside Fairy Shrimp
- Roan Mountain Bluet
- Roanoke Logperch
- Robbins' Cinquefoil