Does this climbing or sprawling plant seem familiar? It was in flower in midsummer. The effect is a little like Pileostegia, but that's not what it is.
Geoff, I wonder if it might be a Celastrus sp. The leaves and growth habit fit very well, but the flowers bother me somewahat. In your 3rd pic I can see the flowers have a broad disc inside the petals characteristic of (but not confined to) Celastraceae. The stamens seems to be inserted below the edge of the disc and radiate horizontally. In photos I can find of Celastrus spp. the petals form more of a cup enclosing the disc and the stamens point upward. The 2 spp. with nicely matching leaves are the N American C. scandens and the Asian C. paniculatus. It cannot be Hydrangeaceae as all its members have "leaves opposite, bases joined by lines across the stem" (Angiosperm Phylogeny Website).
Thanks for the suggestion, Tony. Celastrus does look like a good possibility. Regrettably, I never saw any fruit on it and the building on which it was growing has since been demolished; one of the many casualties of our earthquakes.
That Celastrus suggestion got me looking at the wider Celastraceae and I think it may Tripterygium regelii (http://www.esveld.nl/htmldiaen/t/trrege.htm) or maybe Tripterygium wilfordii. The images I've seen of these species are pretty variable, though, so I can't tell for sure.
That's looking much more like it, don't you think - I mean the species in your link. Another feature is the more richly branched and elongated panicle than seen in Celastrus pics.
I was able to find a little of the plant remaining and it had seed capsules. It is Tripterygium wilfordii.
