These flowers are very tiny—less than a millimeter across.
This second one isn't being posted because it's a favorite; just to give a sense of the scale of these tiny flowers, by showing them against a standard American dime.
For those of you who are not Americans, and not familiar with American coinage, the dime is the smallest current American coin, being approximately 0.7 of an inch, or 18 millimeters in diameter. It has a value of 1/10 of an American dollar.