I mentioned wanting to know the name of this in another thread, thinking it was something really common, and when no-one replied, I decided to post it for ID, but then I actually found it: Muehlenbeckia complexa, wire vine. It's a dense, kind of pillowy ground cover, with sparse leaves on impossibly thin, wiry but not brittle stems. I have seen it in two locations, and until yesterday, was going to say that I had not seen flowers. But today, there are several flowers, around 5mm in diameter, in clusters of mostly three. The leaves are alternate, a little over 1cm long (and across). @pierrot posted a very complete description of it years ago, at Muehlenbeckia complexia or axillaris or nana ?. Male and female flowers are on separate plants. This plant is female.