Pygmy Chain Sword

Helanthium tenellum, known for many years as Echinodorus tenellus, is a small relative of the Amazon sword. It forms small rosettes 5–10 cm tall, made of very thin, grass-like leaves. New plants keep appearing at the ends of thin runners stretching between the rosettes, and over time a soft lawn develops in the foreground.

It is an easy plant; it survives and spreads under medium light in an aquarium without CO₂. Under strong light the leaves get shorter and their tips can turn reddish brown. When light is weak, the leaves grow longer and sparser.

• Separate the rosettes one by one, trim the roots slightly and plant them 2–3 cm apart.
• The center of the rosette (the crown the leaves grow from) should stay just above the substrate; if buried, it can rot.
• Even sparse planting over a wide area of the foreground is enough; the runners fill the gaps over time.

• Light: Medium; strong light is better for a short, dense lawn.
• CO₂: Not required, but speeds up spreading.
• Fertilizer: As a sword plant, it feeds through its roots; root tabs noticeably boost growth.
• Trimming: Usually not needed. Runners heading in unwanted directions are cut.

It multiplies on its own by runners. Once the new plant at the end of a runner has formed a few leaves and roots, the connection to the mother plant can be cut and it can be planted where you want.

• Long, sparse leaves: light is insufficient.
• Yellowing: lack of root nutrients; add root tabs.
• Not spreading: runner formation slows in a very compacted, nutrient-poor substrate.
• Leaf loss in the first weeks: can occur in emersed-grown plants while the leaves are being replaced.