True Forget-me-not
Myosotis scorpioides
From Washington State Dept. of Ecolo
Leaf: Long, narrow alternate leaves are attached directly to the stem and have pointed or rounded tips with a prominent mid-vein. Small flowered: 1.5-10 cm long and 3-15 mm wide. Common: 2.5-8 cm long and 7-20 mm wide.
Stem: Weak and trailing at the base. Small flowered: 10-40 cm long, does not form roots. Common: 20-60 cm tall, often forms roots and new plants at the nodes (stolons). 
Flower: Tiny, short-stalked flowers have 5 blue petals with a yellow center and are arranged along the outside of the coiled stem tip. Blooms from June to September. The base of the petals forms a tube less than or equal to length of the petal lobes. The base of the petals forms a tube longer than length of the petal lobes.
Fruit: Small (each less than 2 mm across), shiny, brown to black "nutlets" in clusters of 4 per flower.
Importance of plant: Some Pacific Northwest Native Americans used small flowered forget-me-not as a "love charm." Also had historical uses by other cultures to treat dog or snake bites. Common forget-me-not is sold as an aquatic garden plant.