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Egeria najas Care Guide

Egeria najas is a fast-growing South American oxygenating stem plant with fine, recurved serrated leaves, tolerant of cool to tropical aquariums.

Overview

Egeria najas is a submerged freshwater stem plant in the family Hydrocharitaceae. It has finer foliage than the closely related Egeria densa, with elongate, toothed leaves usually arranged in whorls of five. The species is a vigorous oxygenator that grows quickly across a wide temperature window.

Taxonomy

  • Family: Hydrocharitaceae
  • Genus: Egeria
  • Scientific name: Egeria najas
  • Common synonyms: Narrow-leaf Anacharis

Habitat

The plant is native to South America, ranging from the state of Minas Gerais in Brazil southwards to northern Uruguay and into Paraguay and northeastern Argentina. It colonises near-shore habitats to depths of about 3 m and tolerates low light and turbid water. Egeria najas is dioecious, producing white three-petalled flowers from an apical spathe.

Aquarium requirements

  • Placement: background
  • Temperature: 16-28 °C (61-82 °F)
  • pH: 6-8
  • GH: 4-18 °dGH
  • Lighting: medium to high
  • CO2: not required (responds to 5-40 mg/L)
  • Maximum height: about 60 cm

Growth and care

Egeria najas is rated very easy and grows fast, making it an effective oxygenator and nutrient sink. It is sensitive to high light combined with poor circulation and benefits from regular trimming, roughly every ten days. The plant cannot grow emersed.

Propagation

Propagation is by cuttings: side shoots and trimmed tops readily form new stems through fragmentation. Stems can be planted in any fine substrate or left floating.

Notes on invasiveness

Outside its native range the species has been recorded as an introduced aquatic weed, including a population in Florida that was eradicated after chemical treatment. Aquarists should never release trimmings into natural waters.

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