Egeria (plant)

Egeria is a genus of aquatic plants native to Brazil. Its species are very popular aquarium plants, as they are very easy to maintain. They also stand out for producing large amounts of oxygen and absorbing many mineral salts.

Description

They are perennial plants, glabrous, submerged in fresh waters; stems erect, with roots at the lower nodes, branched or not; dioecious plants. Leaves simple, whorled, linear, 10–40 mm long and 1.5–4.5 mm wide, serrated, with a vein without acules on the underside; sessile. Solitary and axillary inflorescences; sessile staminate spathe, funnel-shaped to broadly tubular, with 2–4 flowers, spathe pistillate cylindrical, split halfway on one side, with 1 flower; actinomorphic flowers, projecting towards the surface of the water through the base of the thin and elongated hypanthus; sepals 3, herbaceous, green; petals 3, 2–3 times the length of the sepals, membranaceous, white; staminate flowers with 9 free stamens and a small, central, 3-lobed nectar canal; Pistillate flowers with 3 staminodes, 3 carpels, unilocular ovary, parietal placentation. cylindrical fruit; Seeds numerous, fusiform, rostrate, mucilaginous testa.

Ecology

One of the species of egeria or elodea (E. densa) was introduced to the Sacramento River delta in California during the 1960s and since then it has caused a detrimental social impact on the ecosystem of the area. This plant can infect approximately 24 km² or 12% of the total area of the delta area. In several other states it is also considered a problem.
Vegetates in water with depths of less than 3.5 m, so the impact is caused mainly in shallow water. It forms dense bushes that obstruct the passage of boats, clog water intakes and pipes, trap sediments, expel native vegetation and impede the migration of spawning fish.
It is also the cause of part of the environmental problems in Lake Tota in Colombia, where its clogging has contributed to the loss of the reservoir, occupying up to 30% of the lake, in which there can be no life of any kind.

Taxonomy

The genus was described by Jules Émile Planchon and published in Annales des Sciences Naturelles; Botanical, ser. 3 11: 79. 1849. The type species is: Egeria densa Planch

Etymology

Egeria: generic name named for Egeria, in Roman mythology, one of the Camenas, a nymph in the retinue of Venus, who lived in the fountain or spring of Porta Capena in Rome; she was protective of brides as future mothers as well as childbirth. She married Numa Pompilius, "the pious", second king of Rome and taught him matters related to being a just and wise king, inspiring him with religious legislation, teaching him effective prayers and spells.

Accepted species

The following is a list of the species of the genus Egeria (plant) accepted up to September 2014, arranged alphabetically. For each one, the binomial name followed by the author is indicated. abbreviated according to conventions and uses.

• Ageria densa Planch
• Ageria heterostemon Koehler " Bove
• Ageria najas Planch