Echinodorus osiris

Taxobox
color = lightgreen
name = Echinodorus osiris
regnum = Plant
divisio = Magnoliophyta
classis = Liliopsida
ordo = Alismatales
familia = Alismataceae
genus = "Echinodorus"
species = "E. osiris"
binomial = "Echinodorus osiris"
binomial_authority = Rataj in Folio geobot. phytotax. Praha 5:213-4, 1970

In Rataj's taxonomy "E. osiris" is in Section Uruguayensii, Subgenus Echinodorus.

Other authorities consider this species as part of "Echinodorus uruguayensis".

Common name

Melon Sword

ynonyms

"E. osiris rubra" hort.; "E." species "rubra" hort.; "E." Schweden; "E." species; "E. peruensis" var. "rubra"

Distribution

Southern Brazil.Seems to have been first collected by Hans Griem in the 1950's but was re-collected by Thomas Horemann. Found naturally in running, relatively cool waters coming down from the mountains. On the bottom of these rivers it forms stands of hundreds of plants.

Description

Submersed leaves membraneous, young leaves golden-brown, older leaves green, 3- to 60 cm long. Petioles 8 to 20 cm long, blades 20 to 30 cm long by 3 to 5.5 cm wide, oval, on both ends acuminate, having undulate margins and 3 to 5 veins. Veins pseudopinnerved or orientated towards the base. Emerse leaves 50 to 80 cm, occasionally 100 cm, long, petioles irregularly cylindrical, 40 to 70 cm long, blades pvalm or ovate, 14 to 18 cm long by 7 to 10 cm wide having 5 to 7 veins. Emersed and submersed leaves trimmed with distinct pelucid lines.

Stems upright, later deflexed, 80 to 150 cm long, proliferous. Inflorescence racemose or branched in the lower whorl, having 6 to 12 whorls containing 6 to 12 flowers each. Bracts lanceolate, 1.5 to 2 cm long by 5 to 6 mm wide, pedicels 1 to 4 cm long. Sepals 5 to 6 mm long, corolla white, stamens 18 to 24, achenes unknown.

Cultivation

Needs a spacious aquarium with medium-hard water, a good substrate, tropical temperatures (though it can tolerate cooler water). Good light. Propagated by division and by adventitious plantlets. The red colour seems more intense in cooler waters, but seems to fade in iron-deficient waters.

A splendid specimen plant for the larger aquarium.

There seem to be several different forms, including triploid and tetraploid forms. This needs more investigation. No fertile seeds have been observed.

External links

* [http://www.echinodorus-online.de/Deutsch/Arten/osiris/osiris.html in German but good photographs]
* [http://species.fishindex.com/plant_50.html E. osiris]
* [http://www.tropica.dk/productcard_1.asp?id=072 Tropica]
* [http://www.efloras.org/object_page.aspx?object_id=47990&flora_id=1001 photograph]