This purple ground clematis reliably produces a large amount of small white flowers. Does get top heavy so needs a good structure to climb up.
Flammula Group clematis
In Feb 2021 I moved it down to the Main Bed as it did not look very good climbing up a little bit of metal. Hopefully it will scamper amongst the surrounding plants and go some way to covering the metal drain cover.
It had a massive root ball on it, so should do well!