Palmer Amaranth, aka carelessweed and pigweed

Pigweed family - Amaranthaceae Amaranthus palmeri Wats

One of the most common weeds in Cochise County at this time of the year is pigweed. It covers many many hundreds of acres. It is uncommon knowledge that this plant may become potentially toxic to livestock.

The tall summer annual has a stout stem which usually turns red and shorter lateral branches. Ranging from approximately 1 to 6 feet in height, this plant is characterized by towering spikes which are tassels containing oval, reddish-brown seed at maturity.

Considered a pest plant in cultivated fields, it thrives in elevations under 5,500 feet, including desert grasslands and in regions where the soil has been disturbed.

Stockmen prize pigweed and may even take steps to harvest and store it. Because of its benign reputation most individuals may not be aware of its potential toxicity. Pigweed may contain up to 9 percent nitrate, which in turn may be quickly turned into toxic nitrite by a process known as enzymatic action.

All livestock may be affected by the onset of the toxicity which has the following symptoms: death from respiratory failure after rapid and labored breathing, gasping, trembling, and convulsions. Bloating is common in the late stages of poisoning.