Rancheria Clover: Trifolium albopurpureum (Synonyms: Trifolium albopurpureum var. albopurpureum, Trifolium macraei var. albopurpureum) - Possible remnants from Wihelm Suksdorf's former garden in Bingen.
Hare's Foot, Rabbitfoot Clover, Rabbit-foot Clover: Trifolium arvense (Synonyms: Trifolium arvense var. arvense, Trifolium arvense var. perpusillum) -
Golden Clover, Greater Hop Clover, Hop Clover, Yellow Clover: Trifolium aureum (Synonym: Trifolium agrarium) -
Notchleaf Clover, Pinole Clover: Trifolium bifidum var. decipiens - Possible remnants from Wihelm Suksdorf's former garden in Bingen naturalized around that town.
Field Clover, Hop Clover: Trifolium campestre (Synonym: Trifolium procumbens) -
Foothill Clover, Tree Clover: Trifolium ciliolatum -
Bowl Clover, Cup Clover, Wide-collared Clover: Trifolium cyathiferum -
Least Hop Clover, Suckling Clover: Trifolium dubium - A prostrate herb to 6 inches in height. This has typical, but small, clover leaves, with spherical clusters of tiny yellow flowers.
Woolly-head Clover: Trifolium eriocephalum ssp. eriocephalum (Synonym: Trifolium butleri, Trifolium eriocephalum var. eriocephalum) -
Strawberry Clover: Trifolium fragiferum (Synonym: Trifolium fragiferum ssp. bonannii) -
Clustered Clover: Trifolium glomeratum - Possible remnants from Wihelm Suksdorf's former garden in Bingen naturalized around that town, especially around the marina.
Slender Clover: Trifolium gracilentum (Synonyms: Trifolium gracilentum var. gracilentum, Trifolium gracilentum var. inconspicuum) -
Rose Cover: Trifolium hirtum -
Alsike Clover: Trifolium hybridum (Synonyms: Trifolium elegans, Trifolium hybridum ssp. elegans, Trifolium hybridum var. elegans, Trifolium hybridum var. pratense) -
Crimson Clover: Trifolium incarnatum - Possible remnants from Wihelm Suksdorf's former garden in Bingen naturalized around that town.
Hansen's Clover, Long-stalked Clover: Trifolium longipes var. hansenii (Synonyms: Trifolium hansenii, Trifolium longipes ssp. hansenii, Trifolium longipes var. nevadense) - Collected in the upper Hood River Valley.
Long-stalked Clover: Trifolium longipes var. longipes (Synonym: Trifolium longipes ssp. longipes) -
Purple Clover: Trifolium macraei (Synonym: Trifolium macraei var. dichotomum) -
Big-head Clover, Big-headed Clover, Large-head Clover: Trifolium macrocephalum (Synonyms: Lupinaster macrocephalus, Trifolium macrocephalum var. caeruleomontanum) - Wildflower to 8 inches tall. Flower heads clover-like, one to two inches across, ball shaped, pink or red tinged. Leaves palmately compound.
Small-head Clover, Small-headed Clover, Woolly Clover: Trifolium microcephalum -
Thimble Clover, Valparaiso Clover: Trifolium microdon (Synonym: Trifolium microdon var. pilosum) -
Fewflower Clover, Few-flowered Clover: Trifolium oliganthum (Synonyms: Trifolium pauciflorum, Trifolium variegatum var. pauciflorum) - Calyx lobes more or less equal to or less than the calyx tube. Calyx tube split deeply between upper lobes. Calyx lobes long tapered, often to an accuminate tip. Involucre 2-3 mm, generally cut greater than half way to base. Inflorescence 6-10 mm wide, 5-15 flowered. Flowers 5-8 mm long. Leaflets long and linear to obovate.
Purple Clover, 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.
White Clover, Dutch Clover: Trifolium repens (Synonym: Trifolium repens var. repens) - Wildflower to one foot high. Individual flowers like small white claws. Flowers in tight, thumb-sized, round clumps. Leaves in threes.
Teasel Clover: Trifolium retusum -
Burrowing Clover, Subterranean Clover, Subterraneum Trefoil: Trifolium subterraneum -
White-tip Clover: Trifolium variegatum (Synonyms: Trifolium appendiculatum, Trifolium geminiflorum, Trifolium melananthum, Trifolium polyodon, Trifolium trilobatum) - Calyx lobes generally greater than the tube and not deeply split between the upper lobes. Involucre well developed and cut to the middle. Calyx lobes bristle-tipped. Corolla 3.5-1 mm, lavender to purple and typically with white tipes. Leaflets generally obovate or wedge-shaped.
Sand Clover, Tomcat Cover: Trifolium willdenovii (Synonyms: Trifolium tridentatum, Trifolium tridentatum var. aviculare, Trifolium tridentatum var. tridentatum) - Calyx lobes more or less equal to or less than the calyx tube. Calyx tube split deeply between upper lobes. Calyx lobes taper abruptly with bristles at the tip. Involucre greater than 3 mm, cut less than one-half way to base. Inflorescence generally 12-30 mm wide, often greater than 15 flowered. Leaves linear to obovate and serrate-margined.
