American Bistort, Snakeweed, Mountain Meadow Knotweed, Western Bistort: Bistorta bistortoides (Synonyms: Persicaria bistortoides, Polygonum bistortoides, Polygonum bistortoides var. linearifolium, Polygonum bistortoides var. oblongifolium, Polygonum cephalophorum, Polygonum glastifolium, Polygonum vulcanicum)
Brittle Spineflower: Chorizanthe brevicornu var. spathulata (Synonyms: Chorizanthe brevicornu ssp. spathulata, Chorizanthe spathulata) -
Fivetooth Spineflower, Watson's Spineflower: Chorizanthe watsonii - Involucral bracts spine-tipped. Involucres narrowly cylindric. Flowers 1 per involucre. Perianth parted less than one-half its length.
Buckwheats of Oregon: the genus Eriogonum (25 species) - Leaves without stipules at the base of the petiole. Flowers subtended by leaf-like bracts. Flowers in small clusters, each cluster subtended by a bell-shaped or funnel-shaped and often lobed or toothed involucre
Alpine Mountainsorrel, Alpine Mountain-sorrel, Mountain Sorrel: Oxyria digyna (Synonyms: Rumex digyna, Rumex digynus) - 4 sepals. Leaves rounded or kidney-shaped. Flower parts in multiples of 2s . Ovary and fruit 2-sided. Plants of alpine, rocky habitats.
Narrowleaf Oxytheca, Northern Oxytheca, Tree-like Oxytheca: Oxytheca dendroidea ssp. dendroidea (Synonyms: Eriogonum dendroideum, Eriogonum dendroideum var. foliosum, Eriogonum dendroideum var. hillmanii, Oxytheca dendroides, Oxytheca foliosa) - Involucral bracts spine-tipped. Involucres funnel-shaped. Flowers 2 to many per involucre. Perianth parts parted clear to the base. Annual plants of the arid basins.
Bistorts and Knotweeds: the genus Polygonum (Now split into the following additional genera: Aconogonon, Bistorta, Fallopia and Persicaria) - Leaves with sheathing stipules. Flowers not subtended by bracts. Sepals equal in length. Stigma with round cap at its tip.
Docks and Sorrels: the genus Rumex - Leaves with sheathing stipules. Flowers not subtended by bracts. Sepals unequal in length. Stigma much branched.