Elodea densa (Planch.) Casp.

Taxonomic Identity

Elodea densa (Planch.) Casp. is an aquatic plant that grows in water up to 4 meters (13 feet) deep.

Stem Characteristics

It has trailing stems that reach 2 meters (6.6 feet) or longer in length, and produces roots at intervals along its stems.

Leaf Morphology

Its leaves grow in whorls of four to eight, measure 1–4 cm (0.39–1.57 in) long and 2–5 mm (0.079–0.197 in) wide, and have a pointed tip.

Canopy Growth Habit

The stem system grows until it reaches the water surface, where it spreads out to form a thick, dense canopy that blocks light from reaching plants growing beneath it.

Reproductive System

This species is dioecious, meaning male and female flowers grow on separate individuals.

Flower Morphology

Its flowers are 12–20 mm (0.47–0.79 in) in diameter and have three broad, rounded white petals.

Petal Size Dimorphism

Petals on male flowers are 8–10 mm (0.31–0.39 in) long, while petals on female flowers are 6–7 mm (0.24–0.28 in) long.

Tropical Growth Pattern

When grown in tropical environments, Elodea densa typically shows little variation in its growth pattern across the year.

Temperate Growth Pattern

When grown in more temperate environments, the plant spends most of its winter energy producing and storing starch, and puts energy toward canopy growth during the summer.

Aquarium Trade Status

Elodea densa is a popular aquarium plant, but it is no longer sold in some regions due to its invasive potential.

Cultivated Reproduction

All cultivated plants of this species are a male clone that reproduces vegetatively.

Aquarium Cultivation Traits

It grows well in cooler aquariums, is suitable for beginner aquarium keepers, and is easily propagated from cuttings.

Antibiotic Secretion

Reportedly, it secretes antibiotic substances that can help prevent the growth of blue-green algae.

Invasive Traits

It grows best in nutrient-rich, high-light conditions, and has been observed outcompeting native species when introduced to new areas.