Lori Lefevre, age 13, of Eugene, Oregon, for her question:
What exactly is locoweed?
Loco is a word that speaks for itself. We borrowed it from a Spanish word meaning "insane" or "crazy" and extended its meaning, to include whacky and slightly clownish. The locoweed has a loco effect on cattle and other herbivorous animals who eat it.
Actually there are about 100 different locoweeds. They are native wild plants of Western North America and a few of them are deadly dangerous to our cattle, sheep and horses. As a rule, the ranch animals nibble around them and leave them strictly alone. But sometimes the edible greenery of the prairies and ranges is dry and sparse. Then the animals eat locoweeds to fill their hungry stomachs. This is dangerous and often fatal, for these plants contain poisons that seem to attack the animals' nervous systems.
Cattle and horses that have eaten locoweed soon show signs of distress. Their muscles become slow and clumsy and they stumble around in a dopey fashion, maybe bumping into each other. Their eyes are glazed and blurry and food does not interest them. Sometimes they prance and seem to frolic around like clowns. But the unfortunate creatures are poisoned with loco disease and life is not worth living. Unable to eat, they waste away and perish from starvation. Sheep who eat locoweeds may be luckier than the cows and horses.
These wretched weeds are perennial herbs that look like innocent wild plants. You might mistake them for relatives of the wild vetches that belong in the pea plant family. The locoweeds also belong in the Leguminosae family. They are erect little bushes with sprays of small green leaves and dropping clusters of miniature pea shaped blossoms. The most common varieties bear flowers of white, bluebonnet blue or pansy purple. The faded flowers are replaced by miniature peapods and the dry seeds pop out to start a new generation of locoweeds.
Most weeds are rated as pests because they choke out our cultivated plants by stealing air, sunlight and soil chemicals. The locoweeds are more serious pests be¬cause they are poisonous to farm animals. Ranchers do their best to control them. They use tractors to drag sloping disks through the ground. The knife edged metal disks revolve through the plant roots about two inches below the surface. This ends the perennial life of the locoweeds and also destroys a lot of harmless and even useful plants. Some ranchers prefer to attack locoweeds with herbicides. But these weed killing chemicals also may damage plants and animals we want to protect. The best answer to the locoweed may be plentiful supplies of healthy fodder so that animals are not tempted to eat it.
The early settlers had no idea why locoweeds were so dangerous to their farm animals. Modern chemists discovered that the locoweeds have a special ability to absorb these poisons from the soil without being harmed. However, they can and they do hand their deadly doses on to animals that eat their leaves and even their dried out stems.