Ambrosia artemisiifolia plant8 (11741725353)

Description:

Description: Introduced, warm-season, annual, erect herb to 2 m tall. Leaves form a rosette when young; they are grey-green, deeply 2- to 3- divided, hairy underneath and up to 16 cm long. Cream to pale-green male flowers occur in terminal spikes or racemes above the female flowers, which are few in number. Flowering is from late summer to early winter. A native of North America, it is a weed of bare or disturbed areas, such as roadsides, stockyards and stream banks, occasionally pastures; more abundant in the northern half of the region. Can invade and suppress overgrazed pastures, especially if grazed by horses. Seed is spread by water, stock or in fodder. An indicator of disturbance and bare ground. Unpalatable; forms a serious human health hazard, causing hay fever and worsening asthma. Maintaining vigorous pastures with good ground cover is the simplest control method in pastures. Burning, herbicides, hand-pulling, slashing and biological agents can also aid control. Date: 5 March 2009, 09:47. Source: Ambrosia artemisiifolia plant8. Author: Harry Rose from South West Rocks, Australia.