What is Chromolaena?
Other invasive alien plants within the Eupatorieae
Fine hairs giving a soft texture, particularly to younger leaves
Grey-green to dark green
Young leaves often purple, especially when growing in sun
Leaves often larger, more prominently ribbed
Yellow-green when growing in sun, dark green in semi-shade
Young leaves often red, especially when growing in sun
Leaves generally smaller
Broader individual flowers
Bracts with sharp tips, lax around flower-head
Narrower individual flowers
Bracts with rounded tips, tight around flower-head
Larger plants have underground ‘corm’ structure
Branches more lax
More upright growth form, especially young growth in dense stands
May be more fire resistant, resprouting from crown
May be more adapted to tropical conditions
May be more susceptible to fire. Burning frequently kills large plants
May be more cool tolerant (Kriticos et al., 2005)
All AWA chromolaena biotype photos courtesy of Colin Wilson, except for photo of corm from Joshi (2006). All SA chromolaena biotype photos courtesy of ARC-PPRI.
Kriticos, D. J., Yonow, T. and McFadyen, R. E. (2005) The potential distribution of Chromolaena odorata (Siam weed) in relation to climate. Weed Research 45: 246-254.
Joshi, C. (2006) Mapping cryptic invaders and invasibility of tropical forest ecosystems: Chromolaena odorata in Nepal. Dissertation, International Institute for Geo-information Science & Earth Observation, Enschede, the Netherlands.
Zachariades, C., Day, M.D., Muniappan, R. and Reddy, G.V.P. (2009) Chromolaena odorata (Asteraceae) and its biological control. In: Muniappan, R., Reddy, G.V.P., Raman, A. (Eds.), Biological Control of Tropical Weeds using Arthropods. Cambridge University Press, Cambridge. pp. 130-162.