Generalities Sparganium erectum
The Biodo or major cutlass is a perennial rhizomatous aquatic plant, native to the wetlands of the European continent. The fleshy rhizomatous roots sink on the bottoms of small ponds or slow waterways, they are submerged and floating in the water, and from them branch erect stems of light green color, covered with large leaves of the same color, fan-shaped , broad, leathery, which constitute dense tufts that reach dimensions even higher than one meter in height.
The stems of this aquatic plant can reach a height between 40 and 80 centimeters.
As for the flowering of this plant, throughout the summer they produce long stems that carry particular highly ramified inflorescences, consisting of bunches of round, greenish-white glomeruli, the upper ones masculine, the lower female ones. The flowers are followed by fruits, small roundish berries gathered in small tufts.
Its scientific name is Sparganium erectum and is part of the Sparganiaceae family which has about ten species in Italy, present spontaneously. However, there are other varieties of Sparganium such as the angustifolium and the natans, which are always spontaneous and present in Italy as spontaneous.
The biodo is a plant that prefers sunny positions, but develops without problems even in partial shade; it does not fear the cold, and usually it can also be seen in the wild in the streams of our country. It should be placed on the banks of slow waterways or small lakes, taking care to place the rhizomes at a depth equal to their diameter, in fairly fertile and loose soil, in a place that is completely submerged by water.
Sparganium erectum plants can be found in many areas of our country, always being close to ponds and ditches. From the plains up to an altitude of 500 meters, the major cutlass plants effectively colonize many river areas exposed to the sun, and in some stretches, such as coastal areas and areas mitigated by the alpine lakes, it is possible to find larger cutoff species even beyond the 1000 meters of altitude.
The multiplication of the Sparganium can occur by seed or by multiplication.
One proceeds to bury the seeds extracted from the pulp of the small fruits in a compound consisting of sand and peat in equal parts, then place the sowing container in a tray with high sides; the seedbed must be kept underwater until the seeds are completely germinated.
The rhizomatous roots often widen by crawling underground and thanks to these it is also possible to obtain plants by radical multiplication; to get new plants it is sufficient to divide the rhizomes at the beginning of spring and immediately place them at home.
Biodo, Coltellaccio maggiore - Sparganium erectum: Parasites and diseases
As for the diseases that can affect biodo plants, we can say that often the inflorescences of Sparganium erectum are conspicuously ruined by black aphids.
The major cutlass plants are endowed with special phytodepurative properties as they are able to purify the water by filtering the contents in nitrogen and other nutrients. Because of this special property, plants are used to purify the water of ponds and natural pools.