Subclass Rosidae ( Rosidae )
Order Myrtales ( Myrtales )
Family Onagraceae ( Onagraceae )
Continued…
Genus Ludwigia — Ludwigia.
Ludwigia inclinata — Ludwigia inclinata.
“1” South America. A highly variable plant whose appearance is largely determined by growing conditions. This species has a thin, flexible stem bearing alternate lanceolate leaves up to 5 cm long. Depending on lighting intensity, leaf coloration varies from yellowish-green to pink and intense red. Unlike many colorful plants, the leaves are colored not only on the underside but also on top. In aquarium conditions, plants pale, but with good lighting (especially with phytolamps featuring an enhanced light spectrum in the aquarium), the pink color of the leaves is quite intense. Height 20-40 cm. Width 3-5 cm. — Ludwigia inclinata “Tornado” has twisted leaves growing in whorls from thick stems. It grows well in soft and acidic water.
“2” A very demanding plant that requires soft, slightly acidic water with the addition of CO2. Prefers soft water; it is best cared for in an aquarium with acidic and lime-poor water. Temperature 22-30°C, pH 5-7. Strong lighting is mandatory. It is one of the aquarium plants that have the highest light requirements. The greatest decorative effect is achieved under bright, prolonged lighting, which colors the stems and leaves of this ludwigia in brownish-red tones. A slight light deficiency is not fatal to the plant, but causes it to largely lose its extraordinary appeal. Its delicate leaves underwater acquire the same deep red coloration as in their natural habitat only under intense lighting.
Although plants in the aquarium can grow under weak lighting, they quickly lose leaves on the lower parts of the shoots and turn green. Thus, leaf coloration is a good indicator of the plant’s well-being. If the shoots reach toward the water surface, it shows how much they lack light. The substrate plays a secondary role in plant care, although soil promotes growth. Likewise, water circulation contributes to plant development. It reacts positively to liquid fertilizers and additional carbon dioxide supply.
“5” In the aquarium, it forms very picturesque, delicate thickets formed by characteristic needle-like leaves. The stems of this species can easily reach the surface within a week, where they will continue to grow beneath the surface, forming many lateral shoots. It tolerates transplantation easily and starts growing relatively fast. Growth rate is fast. Maintenance conditions are very difficult. Propagation is vegetative by cuttings. You can remove the upper part of the stem while leaving the lower part in the substrate. New sprouts will soon appear at the nodes. The upper parts of the stem can be replanted elsewhere.
Ludwigia inclinata verticillata “Cuba”.
Cuba. Height 10-30 cm. Width 5-10 cm. Grows in swampy conditions, where green leaves are oval in shape, but underwater in the aquarium they become long and narrow, growing very close to each other, making the plant look very compact. New leaves have a copper-marble or reddish-brown tint. Intense lighting, CO2, a well-balanced nutrient regime, and sufficient space for development are required. Without CO2, the plant develops wider green leaves, produces fewer leaves, and grows at a slower pace. Liquid fertilizers with iron and trace elements are mandatory. Plant in the background or as a colorful accent in the center. Due to its large size, it is recommended for wide aquariums. Growth rate is medium. Maintenance conditions are medium. Temperature 20-28°C, pH 5.5-8.0, dH 4-18°.
Identification: Ludwigia inclinata — Ludwigia inclinata.
Ludwigia sedoides — Ludwigia sedoides.
A floating-leaved species. The appearance of this ludwigia is drastically different from the usual. Long stems rising from the substrate are bare for most of their length, and only at the ends of the shoots near the water surface are alternate leaves spirally arranged and densely crowded together. The leaves have varying petiole lengths; the younger the leaf, the shorter the petiole, and the youngest ones located close to the shoot apex are sessile (i.e., without petioles). Due to this arrangement, the leaves form a flat rosette. The stem and leaf petioles are rich in aerenchyma, which keeps the plant afloat. The leaf blade is rhombic, the margin is sparsely serrated, and the color ranges from light to dark green. Leaf petioles are up to 10-12 cm long, brownish-red in color, and the leaf margin acquires the same color.
Old long shoots branch, forming new rosettes. Such young rosettes can be cut off at the branching point and then rooted in shallow water. The longer the stem of the new plant, the deeper it can be planted. A cluster of floating rosettes of Ludwigia sedoides always attracts visitors’ attention. They are undemanding regarding water chemistry, grow at temperatures from 18 to 32°C, prefer shallow water, and enjoy root fertilization. The main requirement is good lighting. These plants will decorate a fairly brightly lit paludarium or shallow aquarium. However, they can also be successfully grown in deep aquariums if planted in pots suspended near the water surface.
Ludwigia helminthorrhiza — Ludwigia helminthorrhiza.
“1” South and Central America. In nature, it often creates a floating carpet along river banks and in small ponds and lakes. Plants have floating shoots with a heavily developed root system that provides a good shelter for fry. The stem is thin, leaves are alternate, often arranged in close pairs, on short petioles, rounded, green. However, this species does not form underwater leaves. All leaves that end up underwater after planting are quickly dropped.
At the end of the stem buried in the substrate, a bunch of small but numerous roots is formed, while the part of the shoot floating on the water forms not only leaves but also special air “float-roots”. The “float-roots” look like small elongated barrels or oblong children’s balloons of bright white (I would even say snow-white) color. These white “barrels” are filled with a special tissue – aerenchyma, which contains many air spaces, thereby keeping the ludwigia shoots on the water surface. The delicate green of the leaves combined with the bright whiteness of the air “float-roots” looks very impressive. Height 2-4 cm. Width 5 cm.
“2” Temperature 15-30°C. Undemanding to water chemistry. pH 5.0-9.0. Lighting is strong. Requires plenty of light, which makes the leaves rounded and reddish-tinted. Under very high lighting levels, it can be very beautiful, with reddish-brown leaves and very short distances between the leaves.
“5” Unsuitable for keeping in an aquarium because it is extremely light-demanding. It can be planted in the substrate, but then it will grow slowly and stretch out heavily. Maintenance conditions are difficult. Very suitable for open aquariums and garden ponds.
Heteranthera zosterifolia, Heteranthera dubia.
Ludwigia repens x arcuata, “Rubin”, Ludwigia palustris, Ludwigia arcuata . 
