Yarrow is a white wildflower—well, it is usually white, but not always.
Yarrow blooms in the summer across BC. Flowers are grouped in flat-topped clusters. Individual flowers are very small, with white petals and a yellowish center. Actually, what looks to be one of those single flowers is itself a composite of distinct male and female flowers. The female flowers form the yellow center; the surrounded five white petals form separate male flowers.
Now and then—rarely—the male flowers are purple. The second picture shows this.
The yarrow we all know.
The less common, purple yarrow.
Also seen yesterday, and included just for the fun of it, is a tiger lily.