Easily one of the most underrated aquarium plants - I was turned off this stuff as a kid for years because all the books prior had said it "does best in colder water". No it doesn't.
The plants you find in rivers, ponds and streams in the northern Canada do not do well in aquaria but the ones from south of the Mason Dixon line in the US do rather well and remains the most versatile American aquarium plant.
To be sure, I've never had very many tanks at 80F but summer indoor highs of 85F for days or weeks at a time do not seem to bother it and it grows better than most plants in water at room temperature or cooler when many plants would otherwise slow down.
The only downside to this plant is it spoils you: exotic tropical Ludwigias only look a little better than this and grow at, I swear, a tenth of the rate.