From.. https://dlnr.hawaii.gov/hisc/info/biocon...a-odorata/
![[Image: Chromolaena_odorata_by_Ashasathees-300x225-1.jpg]](https://dlnr.hawaii.gov/hisc/files/2021/06/Chromolaena_odorata_by_Ashasathees-300x225-1.jpg)
Close up of C. odorata. Note the three prominent “pitchfork” shaped veins in leaves, giving it the name devil weed.
DEVIL WEED (CHROMOLAENA ODORATA)
• Hawaii Pacific Weed Risk Assessment: High Risk
• Chromolaena odorata, also known as devil weed, siam weed, or bitter bush, is one of the most notorious tropical weeds in the world. Emerging as a shrub that quickly forms dense thickets, it can thrive in all environments except deep shade, flourishing in newly disturbed areas. Each plant can grow up to 12 feet tall and produce 800,000 small seeds in a year, which readily disperse via the wind or burrow into clothing, gear, or fur.
• The plant suppresses the growth of other plants (it’s “allelopathic”), allowing it to grow in dense fire-prone thickets in both native forest and agricultural fields choking out all other plant life. If allowed to spread unchecked, it could easily become ubiquitous across dry to mesic-wet environments in Hawaii.
• Distribution: C. odorata was first detected in Hawai‘i at the Kahuku Training Area on the north shore of O‘ahu in January 2011. The weed has been found in Kahana Valley, Pūpūkea, and ʻAiea on ʻOahu, and has recently been identified in Hilo and the Puna District on Hawaiʻi island. C. odorata is native to Central and South America and is a well-documented pan-global pest in the tropics worldwide.
DEVIL WEED (CHROMOLAENA ODORATA)
• Hawaii Pacific Weed Risk Assessment: High Risk
• Chromolaena odorata, also known as devil weed, siam weed, or bitter bush, is one of the most notorious tropical weeds in the world. Emerging as a shrub that quickly forms dense thickets, it can thrive in all environments except deep shade, flourishing in newly disturbed areas. Each plant can grow up to 12 feet tall and produce 800,000 small seeds in a year, which readily disperse via the wind or burrow into clothing, gear, or fur.
• The plant suppresses the growth of other plants (it’s “allelopathic”), allowing it to grow in dense fire-prone thickets in both native forest and agricultural fields choking out all other plant life. If allowed to spread unchecked, it could easily become ubiquitous across dry to mesic-wet environments in Hawaii.
• Distribution: C. odorata was first detected in Hawai‘i at the Kahuku Training Area on the north shore of O‘ahu in January 2011. The weed has been found in Kahana Valley, Pūpūkea, and ʻAiea on ʻOahu, and has recently been identified in Hilo and the Puna District on Hawaiʻi island. C. odorata is native to Central and South America and is a well-documented pan-global pest in the tropics worldwide.