I have these utricularias, they're rubadubdubbing it in a tub (okay, just my sense of humour). There's two different ones. They appear to have somewhat similar looking flowers, except there's a vast size difference. The smaller one is about 4mm. The larger one is about 15mm.
The smaller I've had for ages. Don't know where it came from but suspect it was with something I got from the floodplains. It's been living happily and multiplying in the bath tub and a few other containers I've placed it in. It flowers almost continuously throughout the year. I've always assumed it was U. gibba.
Then along comes the larger one. I saw a bit of Utric on a water plant I bought so dropped it into the bath tub as well. Looked similar to the original but when it flowered was when the difference became apparent. So I researched it and the closest I can come up with is U. australis. Like U. gibba, it's pretty widespread around the world. They're both aquatics and without the flowers look identical to the naked eye.
Thanks Tommy. They are a fascinating plant, and you can get both aquatics and terrestrials. One big advantage of them, I've had the U. gibba in that bathtub for a number of years and there's never been any mosquito larvae in it yet. They're very efficient at trapping the young larvae. People use them as bio-friendly mosquito controllers in greenhouses and the like.