All Species in Cirsium
- Alameda County Thistle (Cirsium quercetorum)
- Arizona Thistle (Cirsium arizonicum)
- Ashland Thistle (Cirsium ciliolatum)
- Barneby's Thistle (Cirsium barnebyi)
- Cainville Thistle (Cirsium calcareum)
- Cliff Thistle (Cirsium turneri)
- Clustered Thistle (Cirsium brevistylum)
- Cobwebby Thistle (Cirsium occidentale)
- Desert Thistle (Cirsium pulcherrimum var. aridum)
- Douglas' Thistle (Cirsium douglasii)
- Dwarf Thistle (Cirsium drummondii)
- Eaton's Thistle (Cirsium eatonii)
- Edible Thistle (Cirsium edule)
- Elk Thistle (Cirsium foliosum)
- Engelmann's Thistle (Cirsium engelmannii)
- Fewleaf Thistle (Cirsium remotifolium)
- Field Thistle (Cirsium discolor)
- Fish Lake Thistle (Cirsium clavatum)
- Flodman's Thistle (Cirsium flodmanii)
- Fountain Thistle (Cirsium fontinale)
- Franciscan Thistle (Cirsium andrewsii)
- Fringed Thistle (Cirsium centaureae)
- Graham's Thistle (Cirsium grahamii)
- Graygreen Thistle (Cirsium cymosum var. canovirens)
- Hill's Thistle (Cirsium pumilum var. hillii)
- Jackson Hole Thistle (Cirsium inamoenum var. inamoenum)
- Kamchatka Thistle (Cirsium kamtschaticum)
- La Graciosa Thistle (Cirsium loncholepis)
- Lacy Thistle (Cirsium pectinellum)
- Le Conte's Thistle (Cirsium lecontei)
- Longstyle Thistle (Cirsium longistylum)
- Meadow Thistle (Cirsium scariosum)
- Mexican Thistle (Cirsium mexicanum)
- Mojave Thistle (Cirsium mohavense)
- Mountain Slope Thistle (Cirsium scapanolepis)
- Mountain Thistle (Cirsium scopulorum)
- Murdock's Thistle (Cirsium tweedyi)
- New Mexico Thistle (Cirsium neomexicanum)
- Nuttall's Thistle (Cirsium nuttallii)
- Ownbey's Thistle (Cirsium ownbeyi)
- Palo Alto Thistle (Cirsium praeteriens)
- Palouse Thistle (Cirsium brevifolium)
- Parry's Thistle (Cirsium parryi)
- Pasture Thistle (Cirsium pumilum)
- Peregrine Thistle (Cirsium cymosum)
- Prairie Thistle (Cirsium canescens)
- Queen Thistle (Cirsium chellyense)
- Rocky Mountain Thistle (Cirsium perplexans)
- Rose Thistle (Cirsium andersonii)
- Rothrock's Thistle (Cirsium arizonicum var. rothrockii)
- Rydberg's Thistle (Cirsium rydbergii)
- Sacramento Mountain Thistle (Cirsium vinaceum)
- Sand Dune Thistle (Cirsium pitcheri)
- Sandhill Thistle (Cirsium repandum)
- Slough Thistle (Cirsium crassicaule)
- Soft Thistle (Cirsium carolinianum)
- Steen Mountain Thistle (Cirsium peckii)
- Suisun Thistle (Cirsium hydrophilum)
- Surf Thistle (Cirsium rhothophilum)
- Swamp Thistle (Cirsium muticum)
- Tall Thistle (Cirsium altissimum)
- Texas Thistle (Cirsium texanum)
- Thistle (Cirsium ×iowense)
- Virgin Thistle (Cirsium virginense)
- Virginia Thistle (Cirsium virginianum)
- Wavyleaf Thistle (Cirsium undulatum)
- Wheeler's Thistle (Cirsium wheeleri)
- White Thistle (Cirsium hookerianum)
- Whitespine Thistle (Cirsium clokeyi)
- Wright's Thistle (Cirsium wrightii)
- Wyoming Thistle (Cirsium pulcherrimum)
- Yellow Thistle (Cirsium horridulum)
- Yellowspine Thistle (Cirsium ochrocentrum)