Tuesday, May 27, 2008

Echinodorus Amazonicus - Amazon Sword

Echinodorus amazonicus

Amazon Sword
A large E. amazonicus in the author's tank.

The Amazon Sword is one of my most favorite aquarium plants. Its large, lush green leaves make this giant, reaching over 20 inches tall, and the perfect candidate for being a centerpiece plant in larger aquariums. Although it’s a relatively easy, undemanding plant to have, its not suitable for all aquariums due to its tank busting size. My current specimen was a mere 6 inches tall when I obtained it, with 2 months it has grown to over 22 inches tall. The Amazon sword is a popular aquarium plant that has earned its place in the aquarium hobby as being a large, hardy, and beautiful plant.

The leaves of the Amazon sword are light green in color and when observed closely, three “veins” can be seen that run along the length of the leaf. The center vein being the thickest of the three, the other two are approximately ¼ the thickness of the main vein. Hair-thin veins interconnect these three veins by running perpendicular to them. The Amazon Sword easily grows to massive proportions, exceeding 20 inches in height if conditions permit. Often growing to the point of overshadowing other plants, eventually choking them out. The leaves range in thickness of about 1.5-2 inches in thickness at the middle of the leaf, and can reach a length of up to 24 inches, sometimes more under proper conditions.

A close-up of the leaf structure of the E. amazonicus. Notice the 3 main veins, and the numerous veins interconnecting them.

Sword plants typically are root feeders, meaning that they prefer to take in nutrients from the substrata rather than from the water column like other plants such as stem plants, and the Amazon sword is absolutely no exception. Its benefits, and prefers to have a rich substrate in which it can thrive. I have managed to grow mine in a sand substrate that is relatively low in nutrients, but I added fertilizer tabs to the base of the crown every couple of weeks and have seen wonderful growth from it. In my opinion, a deep substrata is also a beneficial factor in the growth and development of this plant, on my specimen, the root system is over 10 inches long. A deeper substratum will allow for proper root growth and will lead to a healthy plant, my substrata is about 2.5 – 3 inches deep. An Amazon sword that is doing poorly will discontinue growing new leaves, begin turning yellow around the edges of leaves especially younger leaves that are still in development, and the excess growth of nuisance algae on the leaves. The two main causes of these symptoms are often a lack of certain essential nutrients or a lack of proper or sufficient lighting. Amazons generally grow rather slowly but when given proper conditions, it will flourish and can quickly get to the point of choking out other plants. They prefer medium to high lighting, but will “survive” at lower levels. I keep my specimen at 2.3 WPG, with CO2 injection and it has thrived. The addition of CO2 is another factor that will increase the well being of the sword, but in my opinion, substrate nutrients and lighting are more essential to getting good growth with CO2 only helping the plant along.

Propagation of Echinodorus amazonicus is through two methods, runners and seeds. When submerged and in very a highly humid emerged environment, the Sword will send out runners, on which small plantlets will develop. Plantlets that develop on emerged plants will not develop roots until they are completely submerged. Once the plantlets have become of a good size, remove them from the runner while avoiding any damage to the runner because even after the plantlet is removed the runner will continue to develop more plantlets. The second method, by seeds, is a little more difficult to accomplish. Echinodorus amazonicus will develop small flowers when both submersed and when emerged. Only when the plant is emerged will the flowers open, at which time the fertilization process can be initiated by using a feather to spread the pollen. The seeds will begin to develop, often taking long periods of time.

In conclusion, the Amazon sword is a wonderful addition to any larger sized aquarium that harbors the appropriate conditions. Its size permits it to be both an accenting addition to an aquascape or the centerpiece. Providing the proper conditions for this beauty will give you the opportunity to enjoy one of the best aquatic plants in the aquarium hobby.

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