User:SCBE252-2017-Milantee

Names

Scientific name : Arundo donax Common name : Giant reed, Spanish reed Family name : Poaceae

Origin & distribution

Arundo donax may be a native of the tropical or Mediterranean regions of Eurasia, or it may have originated from Southern Asia and then been introduced to Europe. It was used by the Egyptians 7000 years ago. It is now widespread in the Mediterranean Basin and all tropical areas worldwide. It was introduced to the Americas as an ornamental plant and escaped into the wild. It is naturalized and invasive in subtropical USA, Mexico, the Caribbean Islands, South America, the Pacific Islands, Australia, New Zealand and South Africa (Csurhes, 2009; CABI, 2014; Ryan, 2001). Arundo donax is a semiaquatic plant found in damp areas or riparian habitats such as riverbanks, lakesides, edges of stream and ponds. It does well in moist disturbed places, such as flood plains, coastal areas, roadsides, marshes, sand dunes near seashores or along irrigation ditches and waste ground (Quattrocchi, 2006). In California, it is abundant in large low-gradient river areas, where it covers between 13 and 40% of the surface area (CIPC, 2011). Arundo donax does well under warm temperate and subtropical climates but stops flourishing under a true tropical climate. It has little tolerance to frost (Perdue, 1958 cited by Csurhes, 2009) and does not survive in areas with prolonged or regular freezing temperatures (DiTomaso et al., 2003 cited by Csurhes, 2009). In wetter regions, such as the Fiji Islands, Arundo donax can be found away from riparian areas up to an altitude of 200 m. In the Himalayas, it has been found as high as 2400 m (Perdue, 1958 cited by Csurhes, 2009). Arundo donax grows in a wide range of soils, from coarse sands or gravelly soils to heavy clays and river sediments, and from freshwater to semi-saline soils on brackish estuaries, as it has a degree of salt tolerance (CABI, 2014).

Arundo donax.

Arundo donax.

Morphology

Arundo donax is one of the tallest erect herbaceous grasses, growing to a height of 2 to 6 (up to 10) m. It is a perennial, semiaquatic rhizomatous plant that forms clumps and dense swards. Its short rhizomes form compact bundles that grow into an extensive fibrous root system. The culms, which originate from the rhizomes, can be up to 1-4 cm in diameter. They are erect, hollow with thick (2-7 mm) siliceous walls, smooth, glossy green in colour when young and yellow at maturity or during winter or droughts (Clayton et al., 2012; CABI, 2014; Quattrocchi, 2006). The leaves are alternately arranged with linear-lanceolate and smooth leaf-blades, blue-green in colour and 20-80 cm long x 1-7 cm broad. The inflorescence, borne at the apex of the culms, is a compact silky-hairy feathery plume-like panicle, 30-60 cm long x 5-10 cm broad. The fertile spikelets are pedicellated, solitary and hairy (hairs up to 7 mm long). The fruits are ovoid caryopsis, 2 mm long (Clayton et al., 2012; CABI, 2014; Quattrocchi, 2006). Arundo donax may be difficult to distinguish from other large reeds, such as the common reed (Phragmites australis) or the Burma reed (Neyraudia reynaudiana), but it has broader leaf blades (eFloras, 2014).