Echinodorus opacus

Echinodorus opacus is a compact Brazilian species with oval to elliptic leaves bearing a distinctly matte, almost waxy surface texture — quite different from the glossy leaves of many Echinodorus. The dark-green to olive-green foliage has a subdued, velvety quality that makes it an understated but highly appealing midground plant, particularly in low-light and low-tech setups where more demanding plants struggle. It typically reaches 15–30 cm.

True to its species name, E. opacus has opaque, non-translucent leaves that absorb rather than transmit light. This characteristic makes it one of the better sword plants for shaded positions in the aquarium, such as under overhanging stem plants or next to taller background species. Growth is slow but steady, and the plant maintains a tidy, contained rosette that does not quickly outgrow smaller tanks.

Its tolerance of low light and modest nutrient demands make E. opacus an excellent choice for planted tanks that prioritise low maintenance and natural aesthetics over high growth rates.

Light: Low to medium (20–45 PAR); one of the few Echinodorus that genuinely thrives in low light. CO2: Not required; growth is slow with or without CO2 supplementation. Fertilisation: Root tabs every 4 months; low-dose liquid fertiliser every 1–2 weeks. Placement: Midground; suitable for shaded positions under taller plants; keep crown above substrate. Propagation: Slow to produce runners; daughter plants appear on flower stalks — sever once established.