I'm sticking my neck out a bit on this one, but on my photos of T. tuberosus the anthers are always white, and on T. juncifolius purple, even though the books don't mention this as a distinguishing feature. The flowering stem of T. tuberosus is said to be much branched, while this thing looks to have few branches.
HI Jackie that's fantastic info, thank you, I've updated the sightings with a couple of other pics which may help to show the flowers - 5 or 6 - on the branch. The branches are so spindly they are very hard to photograph, especially here with a phone camera. Thanks again for your interesting info.
Yeah, I think 5 or 6 flowers per stem is what juncifolius should have. T. tuberosus often has lots - I photographed one in a burnt area the other day that must have had 20 or more.