Rabbitfoot Clover, Rabbit-foot Clover, Hare's Foot: Trifolium arvense (Synonyms: Trifolium arvense var. arvense, Trifolium arvense var. perpusillum) -
Golden Clover, Greater Hop Clover, Hop Clover, Yellow Clover: Trifolium aureum (formerly Trifolium agrarium) -
Beckwith's Clover: Trifolium beckwithii -
Field Clover, Hop Clover: Trifolium campestre (Synonym: Trifolium procumbens) - near Klamath Falls, OR and northeastern WA
Foothill Clover, Tree Clover: Trifolium ciliolatum - ??
Bowl Clover, Cup Clover, Wide-collared Clover: Trifolium cyathiferum -
Douglas' Clover: Trifolium douglasii - NE OR, SE WA
Suckling Clover, Least Hop Clover: Trifolium dubium -
Woolly-head Clover: Trifolium eriocephalum ssp. arcuatum (Synonyms: Trifolium arcuatum, Trifolium eriocephalum var. piperi) - Strawberry, Blue & Wallowa Mts.
Cascade Woolly-head Clover: Trifolium eriocephalum ssp. cascadense - E. base of Cascade Mts.
Cusick's Clover, Cusick's Woolly-head Clover: Trifolium eriocephalum ssp. cusickii (Synonyms: Trifolium eriocephalum var. cusickii, Trifolium eriocephalum var. harneyense) - Elkhorn Mts. to S. Central and SE OR
Woolly-head Clover: Trifolium eriocephalum ssp. eriocephalum (Synonyms: Trifolium butleri, Trifolium eriocephalum var. eriocephalum) - E. base Cascades, Siskiyous (and scattered in Blue mts ?)
Strawberry Clover: Trifolium fragiferum (Synonym: Trifolium fragiferum ssp. bonannii) -
Plummer's Clover: Trifolium gymnocarpon (Synonyms: Trifolium gymnocarpon ssp. plummerae, Trifolium gymnocarpon var. plummerae) -
Alsike Clover: Trifolium hybridum (Synonyms: Trifolium elegans, Trifolium hybridum ssp. elegans, Trifolium hybridum var. elegans, Trifolium hybridum var. pratense) -
Crimson Clover ?: Trifolium incarnatum (Synonym: Trifolium incarnatum var. elatius) -
Twin Clover: Trifolium latifolium -
Leiberg's Clover: Trifolium leibergii -
Elmer's Clover, Long-stalked Clover: Trifolium longipes var. elmeri (Synonym: Trifolium longipes ssp. elmeri) -
Hansen's Clover, Long-stalked Clover: Trifolium longipes var. hansenii (Synonyms: Trifolium hansenii, Trifolium longipes ssp. hansenii, Trifolium longipes var. nevadense) -
Long-stalked Clover: Trifolium longipes var. longipes (Synonym: Trifolium longipes ssp. longipes) -
Long-stalked Clover: Trifolium longipes var. multiovulatum (Synonyms: Trifolium caurinum, Trifolium covillei, Trifolium longipes ssp. caurinum, Trifolium longipes ssp. shastense, Trifolium longipes var. shastense, Trifolium oreganum var. multiovulatum, Trifolium rubyi ssp. caurinum) -
Long-stalked Clover, Many-stalked Clover: Trifolium longipes var. multipedunculatum (Synonyms: Trifolium longipes ssp. multipedunculatum, Trifolium multipedunculatum, Trifolium rusbyi ssp. multipedunculatum) -
Droopflower Clover, Long-stalked Clover: Trifolium longipes var. reflexum (Synonyms: Trifolium rusbyi ssp. reflexum, Trifolium longipes ssp. reflexum, Trifolium oreganum var. rydbergii) -
Chilean Clover: Trifolium macraei -
Big-head Clover, Big-headed Clover, Large-head Clover: Trifolium macrocephalum (Synonyms: Lupinaster macrocephalus, Trifolium macrocephalum var. caeruleomontanum) -
Small-head Clover, Small-headed Clover, Woolly Clover: Trifolium microcephalum -
Thimble Clover, Valparaiso Clover: Trifolium microdon - ??
Tomcat Clover, Sand Clover: Trifolium obtusiflorum (Synonyms: Trifolium tridentatum, Trifolium tridentatum var. tridentatum) -
Few-flowered Clover: Trifolium oliganthum (Synonyms: Trifolium pauciflorum, Trifolium variegatum var. pauciflorum) -
Owyhee Clover: Trifolium owyheense -
Plumed Clover: Trifolium plumosum ssp. plumosum (Synonym: Trifolium plumosum var. plumosum) -
Red Clover: Trifolium pratense (Synonyms: Trifolium pratense var. frigidum, Trifolium pratense var. sativum) -
King's Clover, Shasta Clover: Trifolium productum (Synonyms: Trifolium kingii, Trifolium kingii ssp. productum, Trifolium kingii var. productum) -
White Clover, Dutch Clover: Trifolium repens (Synonym: Trifolium repens var. repens) -
Thompson's Clover: Trifolium thompsonii -
White-tip Clover: Trifolium variegatum (Synonyms: Trifolium appendiculatum, Trifolium geminiflorum, Trifolium melananthum, Trifolium polyodon, Trifolium trilobatum) -
Tomcat Clover, Springbank Clover: Trifolium willdenowii -
Cows Clover, Salt Marsh Clover, Springbank Clover: Trifolium wormskjoldii (Synonyms: Lupinaster wormskioldii, Trifolium fendleri, Trifolium fimbriatum, Trifolium heterodon, Trifolium involucratum var. fendleri, Trifolium involucratum var. fimbriatum, Trifolium involucratum var. heterodon, Trifolium involucratum var. kennedianum, Trifolium kennedianum, Trifolium spinulosum, Trifolium willdenowii var. fimbriatum, Trifolium willdenwoii var. kennedianum, Trifolium wormskioldii var. wormskioldii) -