1. Carelessweed, Pigweed (Amaranthus spp.) Annual weedy herbs vary in growth forms from prostrate to branching upright. Toxic agent is nitrate. Animals with acute nitrate poisoning are often found dead with no previous history of illness.

2. Lechuguilla (Agave lechuguilla) Sheep and goats are poisoned most often under range conditions. Cattle are poisoned somewhat less frequently, although this plant can seriously threaten cattle during extended drought. Horses are not known to be poisoned.

3. Antelopehorn Milkweed (Asclepias asperula) An erect-stemmed plant growing to about 15” tall. Abundant in western Texas. Toxic agents involved are resinoids and glycosides. Poisons all livestock, especially sheep.

4. Broad-leafed Milkweed (Asclepias latifolia) Perennial, stout simple stems and four or more pairs of large thick leaves, flowers are greenish to white, giving rise to two to four smooth pods- July to October. Poisons cattle and goats, but more often sheep.