Arundo

Arundo is a genus of plants in the Poaceae family (formerly called Gramineae).

They are grasses with hard canes, generally hollow, they are usually very tall plants, they form dense clumps, with erect stems and without basal ramification. The Arundineae tribe is characterized by being very robust plants over 1.5 meters tall, with sub-woody canes and spikelets with long hairy lemmas or rachilla. They prefer a fertile, humid soil, in a place protected from the sun, preferably by water. It tolerates a pH in the range of 5.5 to 8.3. But it also thrives on all kinds of soils, from heavy clays to loose sands and gravelly soils. This genus contains six species spread throughout all warm countries: A. donax L., A. conspicua G.Forst., A. pliniana Turra, A. formosana Hack., A. fulvida Buchanan, A. richardi Endl.

Description

The genus Arundo is the largest of the grasses of the Mediterranean region, they grow in tight groups, form dense reed beds with abundant liniar leaves arranged conspicuously in two rows along the stems to 3-6 m high, occasionally to 10 m, with leaves 30-60 cm long and 3-6 cm wide, purplish-green at first and yellow when ripe. They are plants similar to Bamboo, from which it differs because from each node comes a single leaf that encases the stem. They are plants that have rhizomes, the stem becomes hard and woody the second year, and that is when it flowers, during the months of September and October, its flower is an inflorescence distributed in a wide structure called the terminal panicle, very feathery and often purple, tall and very decorative. It has very small and inconspicuous flowers, these are found in the apical area of the stem, the panicle is made up of spikelets with always perfect flowers, they are multiflorous, with glabrous rachilla articulated above the glumes and between the anthecia. Generic characters: They are tall, perennial plants with thick, woody rhizomes. Hollow shaft with extravaginal innovations. Membranaceous ligule, very small. Leaves distichous, linear or linear-lanceolate, uniformly distributed on the stem, which has internodes of equal length. Large glumes, almost covering the anthecia, yellowish in color, persistent, membranaceae, glabrous, subequal, lanceolate, acuminate at the apex, 3-5 veined, almost equal to the atencia, approximately the spikelet in length. Mambranaceous lemma, pilose, 3-5 veined, with the median vein prolonged into an awn and also the lateral veins, rarely 2-fida, back covered in its lower half with long silky hairs. Palea small, much smaller than lemma, hyaline, 2-veined. Androecium with three stamens. The seed is oblong with a point, the base of which has a kind of pappus.

Habitat

They are perennial herbs, that is, they grow every year without dying in the winter. "Perennial that grows indefinitely or for at least two years or more.", does not require reseeding each year, belonging to the family Poaceae, native to the region of Eastern Mediterranean to India, China, and Japan. A genus with about 6 species originating from the Old World, now cultivated throughout the world. One species was introduced to America and has become naturalized, and is maintained around homes and cultivated areas, and is even planted in parks and gardens. In the Mediterranean area, it occupies the banks of ditches and canals between crops, forming a large reed hedge, which offers shelter to many species of vertebrates and where birds nest and sleep, for which they are especially considered in some areas and their short or Burning is restricted to periods of the year that do not harm the breeding season. It lives in humid and flooded places, in ditches and watercourses, growing in long colonies. Distribution in Argentina: Buenos Aires, Catamarca, Chaco, Córdoba, Entre Ríos, Formosa, La Pampa, La Rioja, Mendoza, San Juan, Misiones and Salta. Distribution in Brazil: Rio Grande Do Sul. Distribution in Chile: Region I, Region II, Region III, Region IV, Region IX, Easter Island, Santiago Metropolitan Region. In the African continent there are no species of importance.

Propagation

There are two main methods of propagation: division or multiplication from seed. The division must be used in the propagation of all plants that rarely flower, such as some non-native plants that find themselves in a climate other than that of their origin. Dividing is also useful for rejuvenating mature grasses that are very dense and bare in the center. Dividing a herb can be a simple process, as long as it is done at the right time of year. In summer, the grasses produce buds of new growth, some of which are quite large, and which remain dormant until the following spring. As a general rule, it is best to divide herbs just as the buds begin to grow, usually in mid-spring. This fact is especially important because if they are divided at other times of the year, the chances of success will be quite low due to the risk of rot or drought. Other herbs grown in light soils or in warm climates, can be divided in fall. Arundo roots are sensitive to drought, so try to choose a cool, cloudy day for dividing to avoid drying out the roots. The use of thick gloves is also an appropriate measure, since the leaves contain silica and are very sharp. This genus has short and thick rhizomes, with roots at the ends, which form a tight bush. If possible, remove the entire bush and divide the rhizames into pieces, each with several growth buds, taking care not to damage any fibrous roots, and cut the stems down to 30 cm to reduce water loss. To divide, first look for an outlying clump with strong stems and healthy shoots. Dig a trench, at least a shovel's depth, around these to expose the roots, then remove the soil around them to expose the rhizomes leading from the outside towards the main clump, then divide the clump into pieces, each with 2-4 buds minimum, and trim back the rhizomes, then replant them to the same depth as before, water and label. Small pieces of rhizomes that have broken off during division can be grown, as long as they have a healthy bud, discard those with damaged buds and grow the rest in pots, in a frost-free location or in beds of growth for a year, before its final planting. The seeds of this genus are dispersed by the wind. Propagation in greenhouses takes place between the months of February and April. The pots should contain about 3 cm of water to keep the soil moist until the seed germinates. Usually germinates in 1-3 months at 15°C. When they are large enough to handle, the plants are moved into individual pots and continued to grow in the greenhouse, at least through their first winter. Once they reach 20cm or more in height, they can be planted into their permanent positions in late spring or early summer. However, the plants in southern California seem to rarely flower. Arundo does not produce viable seeds in most areas where it has been introduced.

Problems of its propagation

The Arundo, in addition to being a very useful plant, is also considered a noxious weed in Texas, a pest of exotic plants in California, an invasive plant in Hawaii. The main areas of infestation are floodplain rivers in southern California, such as the Santa Clarita River, streams along the central coast, and the Sacramento River delta. The problems with Arundo are numerous, it is so invasive that it can quickly fill up stream channels. This restricts the flow of the water, and modifies the nature of the river. In irrigation canals, weeds can reduce the watercourse to a trickle in a few years. In natural waterways, Arundo is a big problem during floods. Very dense shrublands retain drainage waters quickly, causing water to recede and flood nearby areas. If the flood is large enough to wash away Arundo, it often accumulates under bridges, in culverts, or in other restricted areas, causing structural damage; sometimes even leading to the destruction of these structures by the waters. Another of the problems that it causes is the danger of fires; even when green, Arundo is extremely flammable. When present, fire can spread rapidly, which can completely ruin an ecosystem and worsen sediment carryover in the following year's floods. The rhizomes usually survive these fires, ensuring that the culms will grow back. The cane field is so dense that some animals do not live in it. It is usually used as a roost by many birds. Its roots and stems destroy the habitat of fish. Since Arundo roots are shallower than those of native plants, erosion from an Arundo-infested river may increase. In the Canary Islands, these dense reed beds prevent the natural regeneration of formations of willows, (Salix canariensis), rushes (Juncus acutus and Scirpus holoschoenus), palm groves (Phoenix canariensis), which was a major complication in the great fire in Gran Canaria in 2007. It is believed that the lack of use of this plant triggered its transformation into a problem. On other continents such as South Australia, Arundo has been cultivated for bio-remediation purposes to clean industrial effluents from polluted areas and has also been tested and proven effective in removing salinity in soils, so it could then be used for agricultural activities.

Usage

The leaves are used to make basketry, rugs and gates. Materials are obtained for light construction, used as a windbreak, and for the construction of roofed adobe. It also has medicinal properties, the active ingredients it has are: resins, essential oils, sugars. Mineral salts: silica, calcium, potassium. Alkaloid traces:bufotenidine, bufotenine, dihydrobufotenine, donaxine, donaraxine. Pharmacological action: popularly used as a diuretic, "depurative", galactofuge, anti-inflammatory, local hemostatic. indications: states in which an increase in diuresis is required: genitourinary conditions (cystitis, ureteritis, urethritis, pyelonephritis, urolithiasis), hyperazotemia, hyperuricemia, arterial hypertension, edema, overweight accompanied by fluid retention. Milk hypersecretion. Contraindications: Pregnancy, lactation (it is attributed an inhibitory effect on lactation), arterial hypotension. Do not prescribe dosage forms with alcoholic content to children under two years of age or to consultants in the process of alcohol withdrawal. Side Effects: The fresh plant, by contact with wet skin and subsequent exposure to the sun, can trigger photosensitivity phenomena. Caution / Poisoning: The curaremimetic indole alkaloids present in the flowers (and to a lesser extent in the rhizome) are hypotensive and respiratory depressant (Mulet, 1997). The use of diuretics in the presence of hypertension or heart disease should only be done by prescription and under medical supervision, given the possibility of a decompensation of blood pressure or, if the elimination of potassium is considerable, a potentiation of the effect of cardiotonics. In the East it is of great importance since it was widely used to make paper. For thousands of years, the reed of wind instruments has been built with a thin sheet taken from this type of reed, and many of these instruments are built with the hollow stem of the plant, and are still made with this reed today. this is not a very frequent case, in which modern technology has been unable to develop a satisfactory substitute. The cane of this genus is also cultivated as an ornamental plant; Because it grows quickly and forms compact masses of thick rhizomes, it is used to slow down soil erosion, fix dunes and loose soil along roads and railways. Due to its high growth rate, it is considered an important source of cellulose and paper pulp. With the intertwined stems of the giant cane, panels called reeds are made, which are used to build walls and roofs that can be plastered or covered with mixture (Giant canes are part of the genus Arundo, belonging to the species Arundo donax). It is also used as an auxiliary forage, and can be eliminated by continuous grazing. In orchards its use is frequent, using it as a repair for other crops; the cane serves as a support for various vegetables and fickle plants. Yellow dye is obtained from its pollen. It has high yields as a source of biomass for energy production [7, 269]. Edible uses: the edible parts are: The leaves and root. The rhizome can be eaten raw or cooked, it can also be dried and ground into a powder to make bread, usually mixed with cereal flours. It can also be roasted or boiled.

Caryology

The size and number of the chromosomes is of great importance in the systematics of the Grasses and, from the joint work of Avdulow (1931), almost all agrostologists have taken these characters into account to establish the large groups within of the grasses. There are two extreme types: the festucoid type with large chromosomes and predominant basic number x=7 and the panicoid type with small chromosomes and predominant basic numbers x=9 and x=10. Type festucoid found in almost all tribes of the subfamily Festucoidea, which has large chromosomes and the basic number x=7 predominates, of course with numerous exceptions. The Stipeae tribe of this subfamily has small chromosomes and basic number x=9, 10, 11, 12, 14, 16 and 17. The other subfamilies have a panicoid type, with small chromosomes and predominance of the basic number x=9, 10. In the Bambusóideas, Orizóideas and in the tribe Arundineae, the chromosomes are small and the basic number x=7, 8, 9, 10, 11, 12, 14, etc. Panicoids always have small chromosomes, with a predominantly x=9 or 10 basic number, although there are species with other basic numbers that vary from 4 to 19.

Taxonomy

The genus was described by Carlos Linnaeus and published in Species Plantarum 1: 81–82. 1753. The type species is: Arundo donax L.

Etymology

Arundo: Latin generic name meaning "reed".

Species

• Arundo donax L.
• Arundo formosana Hack.
• Arundo indica Noronha, called in Colombia, Chile, Peru and Rio de la Plata achira
• Arundo plinii Turra