Reaching towering heights of up to 4m, Common Reed is the largest native grass species and it dominates reed vegetation in slow-moving to stagnant wetlands ponds and backwaters. Expansive reed sedimentation zones can be found in the Lower Lobau area of the Donau-Auen National Park.
This perennial grass grows from a network of stout, creeping white rhizomes and can reach 4m in height. The stiffly erect stem is composed of a series of round hollow tubes separated by knotty growth. Roots may be formed around this growth. The bluish-green leaves are attached to the stem by a smooth sheath; leaf arrangement is alternating. Leaf blade is up to 3cm wide. The leaf sheath exhibits a wreath-like growth with short, stiff hairs; this is where the smaller but otherwise similar Reed Canary Grass has a clearly-developed leaf membrane. The flower spikelets have reddish-brown to purple flowers which face in one direction; the spikes are significantly longer than the leaves. Fruits of the plant are hairy and dispersed by wind.
Common Reed is found around the world. It is local to all Austrian provinces, from lower elevations to montane levels and even into sub-Alpine regions. The Common Reed colonizes the sedimentation zones of stagnant and slowly-moving waters, marshy meadows, nutrient-rich bogs and other sites close to the ground water, such as fields located near former creek sections which have now been reclaimed by plants.
Endangerment and Conservation Status
The species is not vulnerable yet is in decline in some areas due to drainage of waters, removal of shore vegetation, and increasing number of (artificial) fish ponds.
The vegetation period of the Common Reed begins relatively late in the year. This perennial grass grows from its powerful system of rhizomes and can reach 4m above water and can penetrate 2m into the water. Leaves can only be assimilated and dropped from the air after they have been flooded for a longer period of time. The hollow, many-chambered blades act like a type of snorkel, transporting oxygen to the rhizomes creeping down in the mud. Many other micro-organisms which would not otherwise survive in the sludge profit from this oxygen supply, which also speeds the decomposition of organic material. The Common Reed begins to flower late, between July and October. Its seeds mature in the winter and germinate in bare dry mud banks; the timing of seed dispersal is thus dependent on lower water levels found in winter. Only a small percentage of the seeds dispersed by wind is actually fertile; Common Reed reproduces mainly by vegetative means through continued growth of its rhizomes.
Throughout history, reed has always been put to practical use in a variety of ways. Today, it is still used as roofing material for dwellings, as interwoven mats for plastering walls, and even as fuel. In the Danube delta, fibres of the plant are used to produce paper after removal of silica. Parts of the plant are used in fodder, and the starchy rootstock can be utilized in the brewing of beer and other alcoholic beverages. Its ashes are often used in mineral-based fertilizers. Common Reed is even put to use in some wastewater treatment plants which use natural, plant-based means to purify water. In addition to these primary benefits, reed beds also provide a habitat for a wide variety of birds – particular types of Bitterns and warblers – which means they provide an invaluable service in the maintenance of the ecosystem.