Description:
Fire-weed is an annual to short lived perennial, erect herb that normally grows 10 to 70 cm high. The leaves are 2-7 cm long and are entire or have lobed or toothed margins. The yellow daisy-like flower heads are loosely clustered. 
As A Soil Indicator:
low Calcium, Very low Phosphorus, High Potassium, High Manganese, High Copper, Low Humus, Compacted Soils, Anaerobic bacteria, High Salt
Life cycle:
Annual, biennial or short lived perennial herb. Seeds germinate at any time of the year when moisture is present with the main germination’s occurring between March and June. The seedlings grow rapidly and flowering commences within 6-10 weeks and continues until mid summer. The top growth dies off in the heat of summer and the plant dies or regenerates in early autumn. The density of Fire-weed varies from year to year depending on seasonal conditions. Plants typically produce 5,000-30,000 seeds per year. It forms a persistent seed bank in the soil. Seed may remain dormant in the soil for 10 years. It is most prolific on low to medium fertility
Detrimental:
Difficult to control. Toxic to horses and cattle. Often causes ill thrift in other grazing stock. 
Toxicity:
Toxic to horses, cattle and alpacas. Sheep and goats are about 20 times more tolerant than cattle because they have rumen organisms that can detoxify the toxin. However deaths have been reported. All parts of the plant at all stages are toxic. Hay, silage and grain contaminated with Fire-weed plants or seeds can also be toxic.

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