Helanthium Tenellum (Pygmy Chain Sword)

Native to North and South America, Helanthium tenellum is a compact, grass-like plant that's earned a solid reputation as one of the more accessible foreground options for planted tanks. The narrow, bright green leaves grow in tight rosettes and stay relatively short under moderate light, which makes it a natural fit for carpeting the front of the aquascape. A red variety exists too, and with strong lighting and a bit of CO2, it'll develop a warm pinkish blush that adds some welcome contrast to an otherwise green layout.

The plant spreads through runners, sending out daughter plants horizontally across the substrate, and with good conditions you'll start seeing that mat develop within a few weeks. CO2 injection isn't strictly required, but you'll notice the difference quickly without it as growth slows and the carpet fills in much more patchily.

Nutrient-rich substrate really helps here since the roots do a lot of the heavy lifting. Plant the rosettes shallowly so the crown stays above the substrate, otherwise they'll rot out.

If you want to see what a well-established carpet looks like, searching planted tank community builds with this species is genuinely inspiring.