Introduced as an ornamental, candle bush can clog creeklines and channels

Urban and surrounding areas

Urban areas are generally the most disturbed and modified, and thus particularly susceptible to invasion by weed species. Weeds such as coffee bush (Leucaena leucocephala) and centro (Centrosema pubescens) are particularly common around urban areas. In addition, ornamental plants may escape from gardens to become troublesome weeds. Examples are candle bush (Senna alata), poinsiana (Delonix regia), morning glory (Ipomea spp.) and snakeweed (Stachytarpheta spp.). The Darwin Botanic Gardens appear to have been the source of mimosa pigra, bellyache bush and cutch tree (Acacia catechu).

Gamba Grass dries out later in the dry season and has a greater biomass than native grasses—increasing the rsik of hot fires

Increased intensity of fires

Gamba grass (Andropogon gayanus) and mission grass (Pennisetum polystachion), both originally introduced as pasture grasses, are especially common in the many very disturbed areas around Darwin. Compared to native grasses such as sorghum, these grasses promote very hot fires which are much more damaging to native trees and shrubs, as well as being more dangerous and difficult to control.