Egeria najas is an undemanding anacharis species that is not yet that familiar in the aquarium hobby as Egeria densa. Like this species, it is native to the southern part of South America (Argentina, Uruguay, Paraguay, Brazil), but its range stretches farther to the north, into the tropical zone of Brazil. This true submerged plant occurs in various flowing and standing waters. The plant has a more delicate appearance than Egeria densa; the leaves are narrower, with clearly visible teeth on the edges. The shoots are densely set with leaves and about 2-3 cm wide.

The Narrow-leaf Anacharis is an adaptable and fast-growing aquarium plant that should be well lit. Nutrient-rich water is very beneficial for its growth, CO2 supply is not always necessary. It can grow floating along the surface but can also be planted into the ground where it anchors itself with few long, unbranched roots. The optimum temperatures lie between 15 and 26 °C; also 30 °C are tolerated, at least temporarily. Egeria najas is more suitable for tropical aquariums than Egeria densa. As well as other stem plants it is easily multiplied by cuttings.

This Anacharis from the subtropics and tropics is versatile and especially recommendable for the initial planting of newly set-up tanks. It is also useful for breeding tanks because it produces a lot of oxygen, takes up excess nutrients from the water column and provides hiding places for the animals. Its deeply green, dense foliage is also decorative in variously planted, rather tall aquariums.