You already have it. It is exactly the same as Hemianthus micranthemoides, though micranthemoides has now been proven to be an erroneous name. The real micranthemoides has not been seen for over 70 years.
:/ I read that too, but I'm not looking for the mystery HM or the round leaved baby tears. Apparently there is a plant that goes under Hermianthus Glomeratus which is a narrower leaved species which will grow to a bush.
The photos on APC are certainly not of the round leaved giant baby tears many of us have now. :O The misnaming and whatever seems to have made it very confusing to ID 3 different plant species.
The narrow leaf is not an emmersed form either as i have round leaved giant baby tears growing emmersed as well. It does not branch and only sends out single side shoots when cut.