Rancheria Clover: Trifolium albopurpureum (Synonyms: Trifolium albopurpureum var. albopurpureum, Trifolium albopurpureum var. neolagopus, Trifolium columbianum, Trifolium columbianum var. argillorum, Trifolium macraei var. albopurpureum, Trifolium neolagopus, Trifolium olivaceum var. columbianum, Trifolium olivaceum var. griseum) -
Branched Indian Clover: Trifolium dichotomum (Synonyms: Trifolium albopurpureum var. dichotomum, Trifolium dichotomum var. turbinatum, Trifolium macraei var. dichotomum, Trifolium petrophilum) -
Narrowleaf Crimson Clover: Trifolium angustifolium -
Hare's foot, Rabbitfoot Clover, Rabbit-foot Clover: Trifolium arvense -
Golden Clover, Golden Hop Clover, Greater Hop Cover, Yellow Clover: Trifolium aureum (Synonym: Trifolium agrarium) -
Bearded Clover: Trifolium barbigerum (Synonym: Trifolium barbigerum var. barbigerum) -
Notchleaf Clover, Pinhole Clover: Trifolium bifidum var. decipiens -
Brewer's Clover: Trifolium breweri -
Field Clover, Hop Clover: Trifolium campestre (Synonym: Trifolium procumbens) -
Nodding Clover: Trifolium cernuum -
Foothill Clover, Tree Clover: Trifolium ciliotatum -
Bowl Clover, Cup Clover, Wide-collared Clover: Trifolium cyathiferum -
Cowbag Clover, Dwarf Sack Clover, Poverty Clover: Trifolium depauperatum var. depauperatum (Synonym: Trifolium depauperatum var. laciniatum) -
Least Hop Clover, Suckling Clover: Trifolium dubium -
Prickly Clover: Trifolium echinatum -
Arched Clover, Woollyhead Clover, Woolly-head Clover: Trifolium eriocephalum ssp. arcuatum (Synonyms: Trifolium arcuatum, Trifolium eriocephalum var. arcuatum, Trifolium eriocephalum var. piperi) -
Cascde Clover, Cascade Woolly Head Clover: Trifolium eriocephalum ssp. cascadense -
Cusick's Clover: Trifolium eriocephalum ssp. cusickii (Synonyms: Trifolium eriocephalum var. cusickii, Trifolium eriocephalum var. harneyense) -
Woolly Head Clover, Woolly-head Clover: Trifolium eriocephalum ssp. eriocephalum (Synonyms: Trifolium eriocephalum var. butleri, Trifolium eriocephalum var. eriocephalum) -
Strawberry Clover: Trifolium fragiferum (Synonym: Trifolium fragiferum ssp. bonannii) -
Bull Clover, Puff Clover, Sour Clover: Trifolium fucatum (Synonym: Trifolium flavulum) -
Clustered Clover: Trifolium glomeratum -
Slender Clover: Trifolium gracilentum (Synonyms: Trifolilum gracilentum var. gracilentum, Trifolium gracilentum var. inconspicuum) -
Rose Clover: Trifolium hirtum -
Canyon Clover, Howell's Clover: Trifolium howellii -
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) -
Beaked Longstalk Clover, Longstalk Clover: Trifolium longipes ssp. caurinum (Synonyms: Trifolium caurinum, Trifolium covillei, Trifolium longipes ssp. shastense, Trifolium longipes var. multiovulatum, Trifolium longipes var. shastense, Trifolium rusbyi ssp. caruinum) -
Elmer's Clover: Trifolium longipes ssp. elmeri (Synonym: Trifolium longipes var. elmeri) -
Hansen's Clover, Long-stalked Clover: Trifolium longipes ssp hansenii (Synonyms: Trifolium hansenii, Trifolium longipes var. hansenii, Trifolium longipes var. nevadense) -
Longstalk Clover, Long-stalked Clover: Trifolium longipes ssp. longipes (Synonym: Trifolium longipes var. longipes) -
Oregon Clover: Trifolium longipes ssp. oreganum (Synonyms: Trifolium longipes var. oreganum, Trifolium oreganum var. oreganum) -
Chilean Clover, Macrae's Clover: Trifolium macraei -
Big-head Clover, Big-headed Clover, Largehead Clover, Large-head Clover: Trifolium macrocephalum (Synonyms: Lupinster macrocephalus, Trifolium macrocephalum var. caeruleomontanum) -
Smallhead Clover, Small-head Clover, Small-headed Clover, Woolly Clover: Trifolium microcephalum -
Thimble Clover, Valparaiso Clover: Trifolium microdon (Synonym: Trifolium microdon var. pilosum) -
Sand Clover, Springbank Clover, Tomcat Clover: Trifolium obtusiflorum (Synonyms: Trifolium tridentatum, Trifolium willdenowii) -
Fewflower Clover, Few-flowered Clover, Sand Clover: Trifolium oliganthum (Synonyms: Trifolium pauciflorum, Trifolium variegatum var. pauciflorum) -
Red Clover: Trifolium pratense (Synonyms: Trifolium pratense var. frigidum, Trifolium pratense var. sativum) - Wildflower to two feet high. Individual flowers like small pink or purple claws. Flowers in tight, thumb-sized, round clumps. Leaves in threes.
Shasta Cover: Trifolium productum (Synonyms: Trifolium kingii, Trifolium kingii var. productum) -
Dutch Clover, White Clover: Trifolium repens - Wildflower to one foot high. Individual flowers like small white claws. Flowers in tight, thumb-sized, round clumps. Leaves in threes.
Persian Clover, Reversed Clover: Trifolium resupinatum (Synonym: Trifolium resupinatum var. suaveolens) -
Teasel Clover: Trifolium retusum -
Siskiyou Clover: Trifolium siskiyouense -
Knotted Clover: Trifolium striatum -
Burrowing Clover, Subclover, Subterranean Clover, Subterranean Trefoil: Trifolium subterraneum -
Suffocated Clover: Trifolium suffocatum -
White-tip Clover: Trifolium variegatum (Synonyms: Trifolium appendiculatum, Trifolium geminiflorum, Trifolium melananthum, Trifolium polyodon, Trifolium trilobatum, Trifolium variegatum var. geminiflorum) -
Arrowleaf Clover, Arrow-leaf Clover: Trifolium vesiculosum -
Sand Clover, Tomcat Clover: Trifolium wildenovii (Synonyms: Trifolium tridentatum, Trifolium tridentatum var. aciculare, Trifolium tridentatum var. tridentatum) -
Cow Clover, Cows Clover, Salt Marsh Clover, Springbank Clover: Trifolium wormskioldii (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 willdenowii var. kennedianum, Trifolium wormskioldii var. fimbriatum, Trifolium wormskioldii var. kennedianum, Trifolium wormskjoldii var. wormskjoldii, Trifolium wormskjoldii) -