Spiked water-milfoil

Water-milfoil (Myriophyllum) — perennial submerged plants of the family Haloragaceae (Haloragaceae), with shoots that rise to the water surface. Long flexible stems are covered with pinnate leaves with very fine segments. The branched stems of water-milfoil catch on paddles and often break off. The plant has a creeping rhizome, from which new leafy shoots quickly grow. Leaves are green or brownish.

The name Myriophyllum comes from two words: miros — countless and phyllum — leaf. Indeed, the long (up to 1.5 m) stems of water-milfoil with leaves deeply divided into filiform segments (diameter 220—380 µm), gathered in whorls, form a dense lacework of underwater growth. At first glance water-milfoil resembles hornwort (Ceratophyllum), but on closer inspection the pinnate leaves of water-milfoil are clearly different from the forked and more brittle leaves of hornwort.

Small pinkish or whitish flowers of water-milfoil are gathered into a sparse spike that rises above the water. Interestingly, a single spike can contain flowers of three types: bisexual, male and female. Water-milfoil flowers are pollinated by wind, although cases of entomophily have been recorded. Wind pollination is aided by thin threads of anthers that are set in motion by the slightest breeze. Self-pollination occurs only as an exception. Sometimes there are stands of water-milfoil with completely sterile flowers. Fruits ripen in mid-September, and a month later they begin to fall, a process that can stretch over several months. Vegetative reproduction is carried out by turions (overwintering buds), as well as by any segment of the stem. There is a clear correlation between sexual and vegetative reproduction — the weaker the fruiting, the more intensively turions are formed.

Underwater meadows of water-milfoil play a very important role in the life of a water body. Large concentrations of small invertebrates are found in its thickets, which serve as food for many inhabitants of the water body. The water-milfoil itself serves as food for herbivorous fish and birds (seeds), as well as a substrate for fish to spawn on and a refuge for the animal life of the water body, especially for fish fry.

Habitat: Spiked water-milfoil grows mainly in still water. It can be found in lakes, quiet river backwaters, oxbow lakes of rivers where pondweeds also grow. It can form dense stands at depths up to 2 m. For normal development the plants require a lot of light. Water-milfoil can be cultivated as a marginal (shore) plant. Planting depth - 10-40 cm. Grows well in open sunny locations or in partial shade.

Reproduction: Vegetatively, by parts of the plant which are lowered into the water or planted on the bottom at a depth of 3—120 cm in spring or summer.

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