Flower identification

(Question)

I’m wondering what kind of flower this is.
She grows at the bottom of your rock garden, between the two bridges. The two blue petals span less than an inch in total.

(Answer)

Your picture is of an alien weed with the common name Asiatic dayflower (Commelina communis), so called because the individual flowers last only a day. It can become a fairly aggressive weed, as it grows quickly, and can root at any of the stem nodes that touch the earth. For that reason, you can find it quickly criss-crossing a garden. However, the shallow roots are easy to pull up.

If it looks slightly familiar, it’s because it’s in the same family as the common garden flower spiderwort (Tradescantia occidentalis). Both have a fleshy stem with nodes, somewhat grassy foliage, and petals with a bit of iridescence.