Subclass Alismatidae
Order Alismatales
Family Alismataceae
Genus Echinodorus
Echinodorus uruguayensis (Horeman’s Echinodorus)
Synonyms: Echinodorus aschersonianus, Echinodorus aureobrunneus, Echinodorus barthii, Echinodorus horemanii, Echinodorus janii, Echinodorus nulliglandulosus, Echinodorus opacus, Echinodorus osiris, Echinodorus pellucidus, Echinodorus portoalegrensis, Echinodorus pusillus, Echinodorus rubra, Echinodorus undulatus, Echinodorus veronicae.
“1” South America, grows in rather cold rivers and streams flowing from the mountains. Forms large, spreading bushes. A very attractive Echinodorus, prone to changing leaf shape and coloration, requiring large volumes. Height 30-50 cm. The diameter of a single bush often reaches 40-50 cm. Leaves grow from a powerful horizontal rhizome. Forms a decorative, dense, vertically oriented rosette. Young leaves grow straight up, pushing the older ones to the sides until they lie on the substrate, forming a hemisphere. Leaf shape is very diverse — from lanceolate to cordate, with clear venation. Narrow, ribbon-like, with wavy edges and a short petiole, 40 cm long, the leaves form a rosette of more than 50 bright green leaves reaching the water surface without making the slightest attempt to emerge into the air. The length and width of the leaves can vary significantly. Leaves of young plants have three longitudinal veins, adults have up to five. As in other Echinodorus of the uruguayensis section, the middle pair of longitudinal veins forms a characteristic “fork”.
Petoiles are usually shorter than the leaf blades. Young leaves are wine-red, red-brown, or reddish-brown, old ones range from brownish-green to dark green. The coloration of young leaves is very diverse — from golden light green to bright crimson. Then the leaves turn green (sometimes golden). The coloration strongly depends on maintenance conditions — primarily lighting and water temperature: the lower the temperature, the shorter the daylight hours, and the higher the illumination, the redder the young leaves and the longer they stay green. The coloration of young leaves is quite stable. Specimens bearing no more than four to five red or pink leaves are most common. Leaves are very rigid; old ones become brittle and break easily. The leaves are quite strong and are not damaged by fish and snails.
“2” Optimum water temperature is 22-24°C, but the plant tolerates a temporary drop in temperature down to 15-16°C. Leaf coloration strongly depends on temperature; leaves with unusually beautiful red coloration occur in cold water during winter months. At 14-18°C, the red coloration of the leaf blades appears. Thus, in colder water, the leaves are colorful, ranging from brown to purple, while in warmer water, green coloration predominates. At high temperatures (above 26°C), it develops quickly, but over time it becomes exhausted and may die.
Water should have a neutral or slightly alkaline reaction (pH 6.8-7.5). Water hardness from 4 to 15°; in harder water, growth slows down, calcium salt crystals are often deposited on the leaf surface, and they become brittle and age earlier. In more acidic and soft water, it grows unsatisfactorily and forms narrow, underdeveloped leaves. Water should be changed weekly by 1/5. Echinodorus does not require intense lighting; on the contrary, excess light “presses” the bush to the substrate, making the plant less interesting. Under moderate lighting, the leaves are raised vertically and have a more elongated shape. In a heavily silted substrate, bright light, long daylight hours, and a low water level, it can form a bog form with small oval leaf blades about 15 cm long, 7-8 cm wide, and long petioles. The duration of daylight is about 12 hours. Under illumination lasting more than 14 hours, the plant produces emergent leaves.
“4” The root system is strongly developed and consists of many straight, almost unbranched “hairy” roots that spread horizontally beneath the substrate surface. It has a powerful creeping rhizome, which even in aquarium conditions can easily reach 2 cm in diameter and 10-20 cm in length within a few years. The old part of the rhizome is bare, bearing neither roots nor leaves, while a lush rosette of leaves and roots grows from the young part. The nature of the substrate is very important for Echinodorus because it feeds through its roots from the substrate. It should be sufficiently nutritious, rich in organic matter, and moderately silted. A nutritious substrate stimulates growth; in case of a micronutrient deficiency, the underside of the leaves pales, indicating the need for fertilization. In very old substrate, Echinodorus roots may rot.
It is very useful to add clay and charcoal regardless of whether the plant is planted in old or new substrate. Fertilizing the plant with divalent iron salts is very important, the lack of which is expressed by the disappearance of red coloration in young leaves and the paleness of old ones. Prefers loose, silted substrate with a high nutrient content, and responds positively to root fertilization. Considering the size of the plant, it is better to use fine and medium gravel or a mixture with coarse sand. Lumps of boiled peat and clay are mixed into it. The substrate layer can be small — about 5 cm. It is best to grow the plant in a separate pot. Mineral fertilizers do not necessarily need to be added to the aquarium water.
“5” Forms large, spreading bushes. It is best suited for large and wide aquariums. Due to the significant size of the adult bush, it is best placed closer to the center in the background. A faster growth rate of new leaves can be noted — the plant usually has two to three young leaves at the same time. Young leaves grow straight up, pushing the older ones to the sides until they lie on the substrate. With significant water pollution by organic and mineral turbidity, the density of the leaf rosette decreases significantly because old leaves die quickly. In an aquarium with a low water level, the plant develops emergent leaves sitting on fairly long and resilient petioles.
Hardiness is so great that there are practically no fish or other animals that can damage it. Due to its powerful root system, it is an ideal plant for digging cichlids and species that lay eggs on plant leaves. By the way, this is almost the only plant that develops wonderfully in aquariums with Malawi cichlids. It produces 2-3 leaves per month.
“6” Propagates by division of the rhizome. Old bushes creeping along the substrate surface form young plantlets from dormant buds on the back of the rhizome. If they are not separated, bizarre rhizome branches form, ending in leaf rosettes. However, in this case, too many buds usually sprout simultaneously, and the young plantlets begin to crowd each other, whereas if they are separated, development slows down sharply. Such formations can be separated, which promotes good growth of the main plant, and planted as independent bushes. Such a rhizome can be cut into parts so that each part has a developed plant. Young plants are separated from the rhizome after forming 4-5 large leaves and 2-3 roots. A 2-3-year-old rhizome yields up to 3-5 young plants per year.
The planting method is also important. It is best to lay the plant on its side and press the root system down with a small stone or glass hairpin. A hairpin can also secure it if roots are completely absent. The substrate should be fairly coarse, smooth, with particles of approximately the same size. Without peat, the root system growth of the plantlets slows down. Because this plant propagates relatively rarely in aquarium conditions, it is not widely distributed among aquarists. Young plants freshly separated from the mother bush usually end up with hobbyists. As a rule, they are quite weak, have poorly developed root systems, and require special care.
Echinodorus barthii — Echinodorus uruguayensis x cordifolius barthii.
“1” Selection form. Synonym: E. “doppeltroter osiris”. This is the reddest of all known Echinodorus to date. Plants usually have 10-15 leaves colored simultaneously. This plant grows very dark, red young leaves that eventually change color to a rich, dark green. Leaf edges may be slightly wavy, curling inward slightly. The red coloration of the leaves persists for a long time. After some time, they turn golden, then green. Old leaves are almost completely black, but usually dark brownish-green. Leaf color changes from dark red in the youngest to dark green in the oldest.
Rhizomatous, rosette plant; leaf blades are elliptic, with a cordate or obtuse base, soft, retaining their red color for a long time. Reaches a height of 30 cm in the aquarium. Leaf length rarely exceeds 22 cm. Leaves are gathered in a rosette, with five arcuate veins, obtusely pointed at the apex and obtuse or with a small cordate notch at the base of the leaf blade. The first pair of veins departs from the central one almost immediately from the base. The rosette is tall but quite loose. Most leaves bend sideways, so the adult plant forms a fairly low rosette with a diameter of no more than 40 cm. Due to this, shading of low-growing aquatic flora occurs only in low tanks where the Echinodorus leaves lie densely on the water surface, preventing free light penetration.
“2” Water should be of medium hardness, with a neutral or slightly alkaline reaction. dH 5-18°, pH 6.5-7. Temperature 22-28°C. Lighting is medium, strong with short daylight hours. Prefers open areas with sufficient illumination. Under strong lighting and a sufficient amount of micronutrients, leaf color becomes most intense. With long daylight hours, it tends to form emergent leaves.
“4” The root system is powerful, fibrous, roots are white, cord-like. The rhizome is usually inconspicuous and grows slowly. The rhizome increases in length at a turtle’s pace. The plant requires a fairly nutritious substrate with the addition of boiled peat. This species is less resistant to chlorosis, so it is advisable to add micronutrients to the water. CO2 supplementation stimulates growth.
“5” A powerful, tall Echinodorus that looks great in a spacious aquarium when planted in its central part or closer to the back wall. Suitable as a solitary bush in small decorative aquariums; in large water bodies, it is best placed between the midground and foreground. Sometimes leaves should be pruned so they do not shade lower-growing plants. Despite the fact that the plant simultaneously has two to three young leaves at different stages of development, the total number of leaves is relatively small — the largest bush bears no more than 50 leaves. This is due to the fact that leaves develop quite slowly, usually no more than two appear per week. In addition, leaves are quite delicate and live shorter than in other related species.
“6” Propagates in the aquarium by daughter plants appearing on the flower stalk. Unfortunately, it propagates quite slowly by rhizome division, so it will most likely remain a rarity and a matter of pride for collectors who own it for a long time.
Identification: Echinodorus uruguayensis.
Echinodorus “Apart”, “Aquartica”, “Aspersus”, “Kleiner Bar”.
Echinodorus palaefolius, paniculatus, scaber, subalatus. 
