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Echinodorus tunicatus Small (1909)
At the beginning of the 20th century the building of the Panama channel enabled the inventory of the native vegetation of Panama. Thus 1908 an up to then unknown species was gathered, and 1909 appeared its first description by Small as Echinodorus tunicatus. In the meantime further occurrences are known by herbarium samples from Costa Rica, Colombia, Ecuador and Peru. The spreading emphasis of this species might be probably Ecuador, Peru and Colombia, as the mass of the herbarium samples proves. Although the first description was made a long time before, this species doesn’t appear often in the literature. Also the appearance of the plant was only known by drawings or by pictures of herbarium samples. Pictorial material or living plants were not to be found despite most intensive search. Therefore I decided travelling to Ecuador to find the plant and photograph and gather material for further investigations. In September/October 2003 it started and I could find in the eastern lowlands of Ecuador, the "Oriente" three locations of this species. Two years later, I found two other locations.
Echinodorus tunicatus is a taxon, which can be found in the undergrowth of the jungle vegetation. It prefers swampy locations at the border of small creaks or in it, but also in small ponds I found this species. The water level has only few centimetres and because the formation of the area it can be assumed that substantially high-water levels are not to be expected. The soil consists of more or less strongly decomposed leaves lying on clay in the underground. Due to the small water level the plants were forced to grow emersed constantly.
The rhizomes of the plant are strong (up to 3 cm and 12 cm long) and erect growing. The leaves have a long petiole with a sheath at the base. The blades are ovate-cordate and the apex acuminate, usually I could find up to 9 veins. The pellucid markings are forming a network independent of the veins. Similarly Echinodorus horizontalis the blades are horizontally aligned in shady places, in order to catch the sparse light as much as possible. In free, full sunny places the blades are more erect, in order to reduce the light stress. The blades are of deep green colour, entire and glabrous. Well developed plants can reach up to 75 cm height and more.
 by the foliage. The inflorescence has 3 to 4 (sometimes 5 or 6) whorls, having a lot of flowers. I could count 58 fruits at one whorl! The flowers have a
diameter of approx. 20 mm and they have 22 to 27 stamens. The fruit has a diameter up to 15 mm and contains more than 200 nutlets. The fruit is separating when mature and the seeds drop out. I could
not recognize any vegetative proliferations at the inflorescences. Obviously the reproduction mechanism is optimized for pure seed spreading.
At the natural locations I could not observe submerged plants. Because the similar environmental conditions (I could observe one E. tunicatus between a lot of E. horizontalis) it can be supposed that this taxon can grow submerged too. At the moment I’m trying to cultivate Echinodorus tunicatus in my aquarium to test, if it is suitable as aquarium-plant. After 2 years of cultivation I believe, that E. tunicatus can be used as aquarium plant. It needs a good fertilized substrate and a lot of light. Then the plant grows sufficiant. My plants don’t like to grow out of the water. But the petioles grow nearly vertically and the blades are horizontally. The plant doesn’t grow as wide as E. horizontalis, so it do need less space in the aquarium.
Echinodorus tunicatus is growing more slowly than Echinodorus horizontalis. From submerged plants I never got inflorescences, so it might be that this plant needs growing out of water to reproduce. |
