Fireweed (Senecio madagascariensis) is a low, upright, short-lived flowering herb that is native to South Africa. It is considered a highly invasive and problematic weed in the state of Hawaii and in Australia. S. madagascariensis has one or several multi-branches stems with alternatively arranged, narrow, hairless, green leaves. It produces multiple loosely clustered, daisy-like bright yellow flowers on the tops of it's branches. Each flower has 13 petals. The flowers mature into white thistle-balls which contain up to 150 thistled seeds. The seeds are dry, cylindrical and slender.
Fireweed Toxic Components
All parts of S. madagascariensis contain hepatotoxic (liver damaging) pyrrolizidine alkaloids. The plants are usually unpalatable to horses, but if not provided with enough pasture grass or hay to graze, they might consume them. Most poisoning cases occur due to contamination of haybales.
- Feed Or Hay Refusal
- Jaundice
- Abdominal Swelling
- Colic Signs
- Behavioral Changes
- Nervousness
- Loss Of Condition
- Secondary Photosensitivity
- Depression
- Death
CHEMICAL CONTROL: Clopyralid, 2,4-D, MCPA, dicamba DGA, glyphosate, and tebuthiuron.
- Mäder G, Castro L, Bonatto SL, Freitas LB. Multiple introductions and gene flow in subtropical South American populations of the fireweed, Senecio madagascariensis(Asteraceae) Genet Mol Biol.. 2016.
- D. Egli & T. Olckers Abundance Across Seasons of Insect Herbivore Taxa Associated with the Invasive Senecio madagascariensis (Asteraceae), in Its Native Range in KwaZulu-Natal, South Africa African Entomology. 2015.
- Cláudio E.F. CruzI,*; Fernando C. KaramII; André C. DaltoI; Saulo P. PavariniI; Paulo Mota BandarraI; David DriemeierI Fireweed (Senecio madagascariensis) poisoning in cattle Pesquisa Veterinária Brasileira. 2010.
- P Motooka, G Nagai, K Onuma, M DuPonte, A Kawabata, G Fukumoto, J Powley Control of Madagascar Ragwort Department of Agriculture, State of Hawaii. 2004.
- Stegelmeier, B. L.; Edgar, J. A.; Colegate, S. M.; Gardner, D. R. Schoch, T. K.; Coulombe, R. A.; Molyneux, R. J. Pyrrolizidine alkaloid plants, metabolism and toxicity. J Nat Toxins, 8(1), 95-116. 1999.
- Samll, A. C.; Kelly, W. R.; Seawright, A. A.; Mattocks, A. R.; Jukes, R. Pyrrolizidine alkaloidosis in a two month old foal. Zentralbl Veterinarmed A, 40(3), 213-218. 1993.
