Q. I have Amazon swords in my 15-gallon aquarium, but after a while they get big. Are there swords that stay small? The fish store has a ‘Rubin’ sword that I would like to get because it’s a nice red color and is about 3 inches tall.
A. Most members of the genus Echinodorus, which includes the Amazon sword (E. bleheri), can get quite large. Echinodorus horemanii, for example, can easily exceed a few feet in height, though a number of cultivars only get to be about a 1 1/2 to 2 feet tall. Some swords can be kept small with vigorous pruning or by limiting the amount of light.
Echinodorus angustifolia is a narrow-leaved member of the genus that often remains no taller than a few inches. However, given plenty of light, nutrients and space, it can develop to three times that height. At that point, you can pull out the large rosettes, leaving behind the newer plantlets that form on the runners. Although E. angustifolia is grasslike in appearance, it doesn’t usually spread out into an even cut-lawn appearance. Nonetheless, it can fill in well enough to make a nice foreground.
There are a couple of Echinodorus that remain very short and have the broader leaves similar to the bleheri. One is the E. parviflorus ‘Tropica.’ This sword was developed by the Danish botanists Niels Jacobsen and Lauritz Holm-Nielsen, and named for the Tropica aquatic plant nursery in Denmark. It grows to about 2 to 4 inches in height, about half the height of other E. parviflorus varieties, and an individual plant will cover an area about 6 inches in diameter. The lancelet leaves get to be about 1/2 to 1 inch in width, with a dark green color and deep texture following the lines of the veins. When mature, it will send out flower stalks, and when the rosette gets large enough, it will develop a second rosette at the base that can be carefully pulled apart from the parent plant or cut with a sharp small knife for replanting.
‘Tropica’ is not an especially fussy live aquatic plant, but with low lighting levels (less than 2 watts per gallon of compact fluorescent light using a good specular reflector), the growth will be almost at a standstill. I recommend that these be grown under moderate to intense lighting (more than 2 watts per gallon) and planted where they will not be shaded by other taller aquatic plants.
This aquatic plant is easily pruned the same way that you would prune an E. bleheri or E. ozelot. Peel and pry away outer leaves as close to the base as possible. You can cut the leaf stem, but this leaves an unsightly stump and can lead to rot that will infect the rest of the plant. Sometimes, leaves cannot be easily reached by hand, yet cutting is necessary for pruning. In my experience, cutting has never resulted in a rot problem — but it is possible, so the preferred method of pruning is with the fingers, peeling away the outside leaves. This aquatic plant looks better when several are planted in a grove. Echinodorus parviflorus ‘Tropica’ can often be purchased from online aquatic plant vendors.
Kristian Iversen at the Aquartica company in Denmark (www.aquartica.dk) has developed a new small sword aptly referred to as Echinodorus ‘Aquartica.’ This plant has a lovely green color just a bit darker than the flesh of a lime but slightly lighter than lime skin. It’s a hybrid developed from several different Echinodorus species, including E. horemanii and round-leaf species. It grows to 4 to 6 inches, covering an area of about the same size. The leaves are about 1 to 1 1/2 inches in width, having a shape very similar to E. bleheri.
Although ‘Tropica’ does not import directly into the United States, I expect this plant will become a popular choice in the U.S. as it enters the country from other sources. Although a slow grower, like parviflorus, it is not a fussy plant, requiring only a modicum of light and nutrients. If amply provided for (2 watts of light per gallon, added CO2 in the range of 20 parts per million and good fertilization), the plant becomes robust. For me, it is a perfect choice for a foreground sword plant, nicely accented by the redder bronze leaves of Cryptocoryne wendtii. The ‘Aquartica’ looks nice as a standalone plant or planted as a grove.
Regarding the E. ‘Rubin,’ this hybrid of E. barthii and red E. horemanii is very easy to grow and has a wonderful sort of red stained-glass appearance. Unfortunately, it grows 18 to 24 inches or more in height, and shades an equally large area. Even with vigorous pruning, a ‘Rubin’ will not fit most aquariums. If a small baby plant is purchased, it can make a striking addition to an aquarium until it outgrows the aquarium.