These blue flowers we found in Australian section of Alpine garden, they are just too beautiful to be a weed.
Can it be Anagallis schliebenii? The only one is suitable for Australian section(fromTanzania) http://en.wikipedia.org/wiki/Anagallis
Probably Anagallis arvensis subsp. foemina (Blue Pimpernel) growing as a weed. Tanzania is in Africa (mixup with Tasmania? ;-)
Yes, thank you, I realized myself later that it is African and it cannot be here. We thought it grows as a weed without label here but so beautiful that we had doubts