Frog in Duckweed, photo by StevesPhotos.
Duckweed biology The representatives of the family Lemnaceae are the smallest flowering plants. They are a distinct group of monocotyledonous plants. Not in without reason they are called the most mysterious of the flowering plants on the Earth. Because of their small sizes they sometimes remain elusive from casual observation.
The size of plants does not exceed 1 cm. Common duckweeds Lemnagreater duckweed Spirodelaand water meal Wolffia are frequently encountered by a number in one place. Lemnaceae - aquatic, either freely floating or submerged for example, ivy leaf duckweed - Lemna trisulcalarger partly long-standing a structly tropical duckweed, Lemna aequinoctialis, from Africa, is considered as the annual plant.
About half of the 30 species of this family dwell in the tropics and the subtropics, the rest - in the temperate zone. The vegetative body of Lemnaceae according to the form resembles the tiny floating sheet or the thallus of the lowest plants; thus for long time they considered to be algae.
No unanimous opinion has been agreed for a word to designate the body of these plants. Until now, since it has been called a fillokladiyem, a vayey, a shield, a plate, a frond, a listets, a stem or a sheet.
In Russia, botanists more frequently is used the term of listets, in foreign countries - fronds. The fronds of Lemnaceae grow either singly or connected in small groups or the networks by the short or elongated legs, formed by the narrow part of the frond transparent thread V.
Type of the right pocket of Lemna gibba. The shapes of fronds are most diverse: The vascular system in Lemnaceae is practically absent, with exception of Spirodela, in the roots of which there are tracheids. Roots are absent or are weakly developed Spirodela and do not reach down to soil.
They are simple, with a root cap, on one or by beams emerging from the abdominal surface of the fronds and fulfilling mainly functions of anchors, which prevent the movement of plants in the water.
The middle part of the frods of Lemna and Spirodela is split by two lateral pockets, in which are embedded the vegetative buds, from which arise daughter fronds during vegetative multiplication.
Sometimes in one of the pockets a flower bud develops.
In the representatives of other species there is one pocket, and it serves exclusively for the vegetative multiplication, whereas the flower bud is highly simplified: A perianth is absent I.
The measurement of a stamen is a little more than 1 mm. Bilocular anthers are fastened to the sealed threads and are supplied with conical pointed svyaznikom. In Finland - are noted 33 cases of flowering fromin Poland - only 2 times within America the flowering of Spirodela in the last years has been observed not more than 20 times.
In Armenia, according to the communication of A. Takhtadzhyana, in in the lakes of the Loriyakay highland plain they observed a mass flowering of duckweed. For the middle strip of Russia within the period from through in published reports appeared only about 25 findings of duckweed flowering.
In the ponds along the Volga river it was possible to observe the yearly flowering of duckweed from through A.
It is possible that the flowering of Lemnaceae is not always noted by botanists because of the microscopic dimensions of the flowers. Duckweeds flower in the summer period, usually during June - August, sometimes at the end of May or during September.
At the beginning of flowering more or less long chains separate into smaller groups, consisting of fronds in Lemna gibba and of fronds in Lemna trisulca. Before beginning flowering, morphological conversions of fronds occur gradually.
In Lemna trisulca vegetative fronds are thinned, become pale, and its "top" is bent downward. In Lemna gibba flowering fronds take on an olive- purple color A.
From the moment of the initiation of flowering fronds to the end of the process of flowering pass about 20 days.Lemna minor: turions never produced and parent plants usually green on lower surface (vs.
L. turionifera, with small, rootless turions mm in diameter sometimes produced and parent plants with red to purple coloration on lower surface). Dawlish Warren has long been recognised as an important botanical site.
Sand Crocus was noted here as long ago as and until a recent discovery in southern Cornwall, the Warren was the only known UK site for this species. 2. Lemna, common duckweeds. 3. Spirodela & Landoltia, the giant duckweeds: A drawing of Lemna alphabetnyc.com drawing shows vegetative plants.
Each new leaf emerges from a cleft or scale in the margin of the last leaf. Rapidly growing plants often have three or four attached fronds, rather than the one or two fronds shown.
This shopping feature will continue to load items. In order to navigate out of this carousel please use your heading shortcut key to navigate to the next or previous heading. Homeopathic Medicines are used for the cure of the diseases.
Every patient is examined completely by a homeopath. After the complete case study, Remedy is prescribed by the Homeo-Doctor to cure the disorder or cause of disease. I removed with Lemna 3x four times a day a very chronic catarrh in a lady, and at the same time made her tolerant of the smell of strong-scented flowers, which she could not bear before.
In a man I cured with Lemna 3x, given three times a day, an aggravated nasal catarrh.