3 flower

1. Prairie spiderwort, Tradescantia occidentalis
2. Dayflower, Commelina erecta

4 flower, outer parts longer than 1/2 in. Page 1
17. Lavenderleaf evening primrose, Calylophus lavandulifolius
20. Plains yellow evening primrose, Calylophus serrulatus
21. Toothleaf evening primrose, Calylophus berlandieri
22. Common evening primrose, Oenothera biennis

4 flower, outer parts shorter than 1/2 in. Page 1
7. Flax-leaved stenosiphon, Stenosiphon linifolius
8. Clammyweed, Polanisia dodecandra
9. Scarlet gaura, Gaura coccinea
10. Hairy gaura, Gaura villosa
11. Velvety gaura, Gaura parviflora

4 flower, outer parts shorter than 1/2 in. Page 2
27. Gordon's bladderpod, Lesquerella gordonii
31. Snow-on-the-mountain, Euphorbia marginata
33. Watercress, Nasturtium officinale
34. Catchweed bedstraw, Galium aparine
36. Water speedwell, Veronica anagallis-aquatica
38. American bugleweed, Lycopus americanus