FAQ - Plants - Ludwigia
The genus Ludwigia comprises several species of disparate form and growing requirements. Haling as they do from a wide geographical range, they are adapted to a broad range of conditions from exposed relatively dry ground to total inundation for months on end. Many are useful in aquaria and ponds alike. This is noted with each of the species listed below. There are said to be 75 species in the genus, not all of these are cultivated. Most of the species are native to the warmer areas of the New World. There are a few endemic to Africa and Eurasia.
The characteristics that are common to all members of the genus are as follows:
1. Leaves are most often alternately opposed, rarely oppositely opposed.
2. Flowers are yellow or white, have 0-7 petals and have 4-7 green sepals, which are persistent. The petals fall off when the flower is spent.
3. Flowers are solitary, axillary (held close to the stem on very short stalks or no stalks at all) or they are produced in terminal clusters.
4. Fruit is a cylindrical capsule. Many of seeds are produced by each flower. This number reaches the thousands in the larger species.
THE SPECIES: (Limited to those species that we carry)
L arcuata. Native range extends from North Carolina to Florida. Perrenial stems grow against the
substrate developing roots at all af the leaf nodes. Leaves are small, growing to only
about ½ long and 1/8 wide, and are stemless. Flowers are yellow and are ½ to ¾
Will grow in shallow water and can become established in mud adjacent to the water,
forming dense mats at the ponds edge. Prefers warm weather and will not tolerate cold winter weather. Will grow in any sandy, and/or loamy soil, or over open water. Will also grow submersed as an aquarium plant in bright light, or as an oxygenator in a pond, although it prefers to be out of the water.
L peruensis. Erect woody perrenial that grows to several feet tall. Flowers are large for the
group, presenting a 1.5 diameter flat disc of 5 bright yellow petals. Flowers are held
on axilary stems that are about ½ long. They are followed by a capsule containing
hundreds of tiny, dustlike seeds. Capsules are as much as 1.5 long.
Leaves are lanceolate, lightly pubescent, up to 4" long and 1" wide. Frost tolerant.
L palustris. Commonly used as an aquarium plant where it forms thickets of roots, stems and
shapely leaves that turn pink or red in bright light. In ponds it is useful as an
oxygenator or as a marginal bog plant. It is useful for covering pond edges or for
growing in moist to semi-dry soil adjacent to the pond. It will grow almost anywhere,
being found in most of the Northern Hemisphere.
Leaves are lanceolate to ovate. They frequently have undulated edges, especially under
water. Submersed leaves may be green, pink, or red, depending on light exposure and will grow to well over an inch long under ideal conditions. Will grow in well lit water up to three feet deep. Emersed leaves are usually dark green with noticeable veins. Flowers are sessile (stemless), axilary (occurring at the base of leaves or their stems, right against the stem), and almost without petals. Four tiny yellow petals sit atop a short, fat seed capsule.
Propagation is by cuttings or by seed. Seeds are very small and can be germinated on any damp, sandy substrate. Cuttings will root within a few days of being cut and will grow quickly thereafter.
L longifolia. Primrose WIllow. Graceful semi-woody stems grow to 5 feet. Leaves are long and narrow (3/8 X 6-),
hence the name, longifolia. Flowers are very similar to L. peruensis, but are cupped. Culture is easy as these will grow in any soil and will root anywhere on their stem.
L repens This is a lovely and useful speceis that has become very well established in the hobby. Its habit
of creeping out over the water surface has kept it in the forefront of many a pond owners
view for many years. Of course, it helps that it produces a steady profusion of
bright yellow flowers through the summer. Its capacity to compete with algae is in its
favor, as well.
Leaves are dark green and have noticeable veins. They are ovate to circular and grow
to about 1 long and ¾ wide. Flowers are produced singly on short axilary stems near
the growing end of the plant. Seed capsule is about an inch long and contains several
L peploides. Native to eastern and southern North America. A much larger version of L. repens. Stems are robust, can grow to several feet long, and become semi-woody over time. Flowers are almost 2" indiameter. Leaves grow to nearly 5" long and are light to medium green with noticable veins. Copius roots make it a very effective filter.