Hymenoxys odorata
| Hymenoxys odorata | |
|---|---|
 | |
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Eudicots |
| (unranked): | Asterids |
| Order: | Asterales |
| Family: | Asteraceae |
| Genus: | Hymenoxys |
| Species: | H. odorata |
| Binomial name | |
| Hymenoxys odorata DC. | |
Hymenoxys odorata is a species of flowering plant in the daisy family known by the common names bitter rubberweed and western bitterweed. It is native to the southwestern United States from California to Texas and northern Mexico, where it grows in dry regions. This is an annual herb producing a branching stem to a maximum height near 60 centimeters. The stems are covered in a foliage of short leaves which are divided into narrow, pointed lobes. The plentiful flower heads contain bright yellow disc florets and about eight short yellow ray florets.
This plant is poisonous to livestock; it is mostly a problem of the sheep industry. The toxic compounds are sesquiterpene lactones called hymenovin[1] and hymenoxon.[2] When ingested by sheep the plant produces inflammation of the stomach, renal necrosis, and toxic hepatitis,[3] as well as inhibition of clotting factors.[4] An ill sheep may be bloated, anorexic, weak, drooling, and vomiting.[5] Acute and chronic, cumulative poisoning is often fatal. Sheep tend to avoid the plant because they find it distasteful but they will eat it in the absence of other forage.[5]
References
- ↑ Poisonous Range Plants of Temperate North America Merck Veterinary Manual
- ↑ Pfeiffer, F. A.; Calhoun, M. C. (1987). "Effects of environmental, site and phenological factors on hymenoxon content of bitterweed (Hymenoxys odorata)". J Anim Sci 65: 1553–62.
- ↑ Witzel, D. A.; Jones, L. P.; Ivie, G. W. (1977). "Pathology of subacute bitterweed (Hymenoxys odorata) poisoning in sheep". Vet Path 14 (1): 73–8. doi:10.1177/030098587701400109.
- ↑ Steel, E. G.; Witzel, D. A.; Blanks, A. (1976). "Acquired coagulation factor X activity deficiency connected with Hymenoxys odorata DC (Compositae), bitterweed poisoning in sheep". Am J Vet Res 37 (12): 1383–6. PMID 999065.
- ↑ 5.0 5.1 Bitter Rubberweed (Hymenoxys odorata) USDA Poisonous Plants Research