Southeastern Arizona plant common names that begin with T.
- Tackstem, White
- Tahoka Daisy
- Takhoka-daisy
- Talinum, Big
- Tall Mountain Larkspur
- Tall Scouring-rush
- Tall White Violet
- Tamarisk
- Tanseyleaf Aster
- Tanseyleaf Goldenweed
- Tanseyleaf Spine Aster
- Tanseyleaf Tansyaster
- Tansy Aster
- Tansy-aster
- Tansy-aster, Desert
- Tansy-aster, Hoary
- Tansy-aster, Mesa
- Tansyaster, Arid
- Tansyaster, Hoary
- Tansyaster, Mesa
- Tansyaster, Tanseyleaf
- Teddy Bear Cholla
- Teddybear Cholla
- Telegraph Plant
- Tenella Mustard
- Tepary Bean
- Tetramerium
- Texas Ageratum
- Texas Betony
- Texas False Garlic
- Texas Sandbur
- Texas Stork's Bill
- Texas Thistle
- Texas Toadflax
- Texas Virgin's Bower
- Texas Zinnia
- Thicket Globe-mallow
- Thimbleflower
- Thimblehead, Trans-Pecos
- Thimblehead, TransPecos
- Thimblehead, Wright's
- Thimblehead, Yellow
- Thistle, Arizona
- Thistle, Desert
- Thistle, Kansas
- Thistle, Mexican
- Thistle, New Mexico
- Thistle, Sow
- Thistle, Texas
- Thistle, Tumbling
- Thistle, Yellow-spine
- Thistle, Yellowspine
- Thorn-apple, Desert
- Thorn-apple, Sacred
- Thoroughwort, Palmleaf
- Threadleaf Ragwort, Smooth
- Threadplant, Glandular
- Three-seeded Mercury
- Threefold, American
- Thurber's Cotton
- Thurber's Desert Honeysuckle
- Tidestromia, Woolly
- Toadflax, Annual
- Toadflax, Moroccan
- Toadflax, Texas
- Tobacco, Desert
- Tobacco, Indian
- Tobacco, Tree
- Tocalote
- Tocolote
- Tomato Weed
- Torrey's Craglily
- Trailing Four O'Clock
- Trailing Windmills
- Trans-Pecos Morning Glory
- Trans-Pecos Morning-glory
- Trans-Pecos Thimblehead
- Transpecos Morning-glory
- TransPecos Thimblehead
- Tree Tobacco
- Trefoil, Broom Bird's-foot
- Trefoil, Foothill Bird's-foot
- Trefoil, Strigose Bird's-foot
- Trefoil, Yellow
- Trembling Aspen
- Trembling Poplar
- Triangle Bur Ragweed
- Triangle Burr-Ragweed
- Triangle-leaf Bursage
- Triangleleaf Bursage
- Tripleleaf Morning-glory
- Trixis
- Trompillo
- True Watercress
- Trumpet Bush, Yellow
- Trumpet-flower, Yellow
- Trumpetbush, Yellow
- Tube Tongue, Longflower
- Tuber Anemone
- Tuberous Sida
- Tubetongue, Longflower
- Tucson Bur Ragweed
- Tucson Burr-Ragweed
- Tufted Evening Primrose
- Tufted Geranium
- Tufted Globe Amaranth
- Tumbleweed
- Tumbling Thistle
- Tuna Cactus
- Turpentine Brush
- Turpentine Bush
- Twinberry
- Twinevine, Fringed
- Twining Snapdragon, Violet
- Twintip, White-woolly
- Twintip, Whitewoolly