Myriophyllum aquaticum stem5 (14647365501)

Description:

Description: Introduced, warm-season, perennial aquatic or semi-aquatic herb that roots freely from the lower nodes. Stems are to 5 m long, often protruding about 30 cm above the water. Emergent leaves occur in whorls of 4-6 and are hairless, grey-green and feather-like (10-18 pairs of leaflets). Only female plants are present in Australia; flowers are solitary and tiny (to 0.5 mm long) in the leaf axils. Flowering is during the warmer months. A native of central South America, it is an escapee from aquariums and water-gardens, and now an environmental weed. Found in shallow, still to slow-flowing, dams, pools and creeks, especially if nutrient enriched. Spread only by stem fragments via humans and water as fruit are not formed in Australia. Can form dense stands that choke waterways and exclude native plants and animals. Control by manual removal over the warmer months; dry out in the sun and don’t dispose of near creeks or ditches. There are no registered herbicides for control. Date: 18 March 2008, 12:36. Source: Myriophyllum aquaticum stem5. Author: Harry Rose from South West Rocks, Australia.