The anacharis is a good choice your betta fish tank, especially for beginners. The anacharis is the most common aquarium plant. It can be left to float, buried or tied to one spot. This plant does not require fertilizer, and it propagates with ease.
Other plants that work well in a betta fish tank include Java fern, Amazon sword plant, hygro-hygrophila and hornwart. Some plants can be buried in the tank's soil, while others should be attached to driftwood. Be careful using hornwart, because it can take over a tank. It also has a tendency to shed needles that land on the bottom of the tank, rot and produce unhealthy water conditions.