Propagating Echinodorus macrophyllus (Big-leaf Sword)
How to propagate the big-leaf marsh sword Echinodorus macrophyllus by adventitious plantlets on submerged flower stalks and by crown division.
Overview
Echinodorus macrophyllus is a huge marsh-form sword from South America, native to Brazil and Bolivia. Its blades are sagittate-cordate or triangularly obovate, roughly 20-30 cm long and 20-30 cm wide on petioles two to three times longer than the blade. It is easy to grow and makes a very good specimen plant for the larger aquarium.
Grown mostly emersed in nature, it will often quickly form emerse leaves in the aquarium, which prefer moist conditions and don't like being dried out by being too near lamps. Propagation follows the rosette pattern: adventitious plantlets and division, not cuttings.
Propagation Method (Adventitious Plantlets / Division)
For Echinodorus, propagation is by division or by adventitious new plants developing on submerged flowering stems. The inflorescence of E. macrophyllus is usually paniculate with 6-13 whorls containing 6-9 flowers each; if that inflorescence forms submersed, small plantlets form instead of flowers, turning the stalk into a source of daughter rosettes.
Where the plant grows emersed and humid it tends to flower and set seed (aggregate fruit globular, echinate, 6-8 mm) instead, so keep the stalk underwater if you want plantlets. Division of the large crown is the other reliable method.
Step-by-Step
- Grow a large, well-fed plant until it produces a paniculate flower stalk.
- Keep the stalk submersed so the whorls form plantlets rather than flowers; anchor it under the surface with thread and a stone if it lifts.
- Allow each plantlet to grow leaves and a root system at the whorls.
- Detach a rooted plantlet and plant it into deep, rich substrate.
- Remove the stalk once all plantlets are harvested.
- Alternatively, divide a mature crown into sections that each retain roots and leaves, then replant with plenty of space.
Conditions for Healthy Growth
Cultivation requires tropical temperatures with plenty of light and a rich substrate; the plant tolerates variable water conditions. Because it is large, give it depth and feeding to support its broad heart-shaped leaves, and keep lamps far enough away that emersed leaves are not scorched.
Maintenance
Remove old outer leaves at the base so the broad blades above receive light. Top up root tabs and keep the substrate deep; thin the leaf canopy if it begins to shade the rest of the tank.