Osiris Sword

The Osiris sword is a hardy Echinodorus species from rivers in southeastern Brazil, producing broad, lance-shaped leaves in shades of green to reddish-brown, with new leaves emerging in a pink-red flush before darkening with age. Some authors consider it a natural hybrid of Echinodorus uruguayensis and another related species. It is one of the easiest large rosette plants for the midground or background of a community tank. Flowgrow lists an optimum temperature of 15 to 26 °C, which is cooler than most sword plants — it tolerates unheated tanks down to about 8 °C but does best in the range of 15 to 26 °C. The pH range is not published on Flowgrow; a practical range of 6 to 7.5 covers most setups. Light should be medium to high; under low light the plant survives but the new leaves stay green rather than showing the pink flush. Carbon dioxide is optional — the plant grows well without it, though CO2 supplementation speeds up leaf production noticeably. Growth is fast once established, and the plant benefits from root tabs or a nutrient-rich substrate because it is a heavy feeder. Spread is by runners, which can be separated once they develop four or five leaves. The difficulty is rated easy on Flowgrow, which is accurate: the Osiris sword is forgiving of temperature swings, variable light, and irregular fertilisation, making it a reliable choice for beginner planted tanks.