Having said in the last post that the plant I thought was Ceratocapnos claviculata lacked tendrils, when I went to the same location I found more plants not only with tendrils, but also developing flowers! Perhaps it only develops tendrils as it flowers? Anyway the most useful key (of the ones I have) for this is Poland and Clement which at least acknowledges that there may be at least occasional hairs and also recognises that the plant is present throughout the year. Stace says it is annual and doesn’t mention hairs at all.
The leaflet lobes of all of the specimens I examined had very fine minute translucent teeth around their edges visible with x 20 microscope but appearing entire through the hand lens. As the plant is everywhere described as having entire leaflets at what magnification do teeth become teeth? The tendrils also have the same minute teeth edges.