Primulaceae

Pimpernel: Anagallis arvensis - Leaves scattered along the stems. 5 petals spreading. Flowers salmon pink.
Chafweed Centunculus minimus - Annual. Leaves scattered along the stems. 4-5 petals spreading. Flowers sessile.
Shooting Stars: The Genus Dodecatheon - Leaves basal. Petals 4-5, reflexed sharply backwards. Flowers pink, rose or purplish (occasionally white).
Cliff Dwarf-primrose, Dwarf Primrose, Smooth Douglasia, Smooth-leaf Douglasia: Douglasia laevigata var. laevigata (Synonyms: Douglasia laevigata, Douglasia laevigata ssp. ciliolata, Doulgasia laevigata var. ciliolata) - Leaves arranged along the stems. 5 petals are spreading. Flowers pink to purple.
Loosestrife: The Genus Lysimachia - Leaves scattered along the stems. 5 petals are spreading. Flowers yellow.
Starflowers: The Genus Trientalis - Leaves crowded at the top of the stem. Petals 6-7, spreading. Flowers white or pink-tinged.