A little spring-fed stream is densely filled with the abundant deep green leaves of a low-growing plant. Petite blue-purple flowers bloom here and there in the foliage. This is American speedwell, or Veronica americana. A splayed pair of stamens surrounded by four small petals (the bottom one sometimes slightly smaller than the other three) are characteristic of the many species of speedwells.
American speedwell (also called brooklime) is native to temperate parts of North America and Asia. This plant loves to grow in slow-moving water, where its fleshy stems grow into a sprawling tangle. It is tart but edible, and high in Vitamin C.
Flowers Of Marin 