i live in Vanuatu (S pacific) and am searching for a decorative leguminous groundcover (ie not for a green manure). Last saw one in Peru in jungle camp, which grew well, didn't need cutting and didn't hold water, ergo no mosquitoes. It had a small yellow flower - no-one seemed to know where it came from, and it is exactly what we need here...help, please!
You may be referring to arachis pintoi, locally known as mani (pronounced "mahNEE"). This plant has been a wonderful ground cover here for me--almost "too good", it spreads so lushly. We have a semi-arid climate here, and on hots days during the dry season, the mani lies down and looks faded, even crispy at times, but with a little rain or irrigation, it pops right back and is flowering again in a few days. It doesn't mind being weed-whacked back severely --the edges look a bit stubbly, but only for a day or so.
This pic was taken only a few months after I planted small, bare-rooted plants on 6-inch centers and kept it irrigated. I'm told it enriches the soil with nitrogen very well. I hear that it can be easily "round-Up'd" or "Weed-b-gon'd", leaving richer soil in its demise.
I love the stuff, tho it takes some tending once it's going.