Still thinking bitterly about the loss of what had been the best part of this job, and had provided Ranny the most excitement he'd experienced in his life, he trundled a handtruck to the haystack and loaded a bale of hay to deliver to stall 17 in the show horse barn. Many owners brought their own hay, but the Cow Palace sold it to those who didn't want to bother trucking their own supply. This was excellent quality alfalfa from a top Central Valley grower, and the price charged was just double the cost. There had been a near disaster one season when a new manager had attempted to maximize profit by buying inferior hay, when a couple of horse owners had found a few dried yellow star thistle plants in the flakes of hay and had threatened lawsuits.
Star thistle wasn't a native California plant but a Mediterranean import, probably introduced accidentally when some of the microscopic seeds emigrated along with some legitimate imports. In its native land a natural form of control was provided by an insect which laid eggs in the flower bud, and the resulting worm ate out the material before it could mature and turn to seed. Integrated Pest Management was being tried in California as an alternative to chemicals, but there was fear that introducing that insect here might lead to decimation of the state's artichoke crop, and that was a very valuable thistle species indeed. The hot, dry climate in the New World's west coast, which allowed alfalfa to be cut every 28 days for up to ten crops a year, suited the newcomer perfectly, and now the noxious weed could be found all over the state. In its early stage in pasture land it was devoured by cattle, who loved the tender green leaves and whose systems digested it with no ill effects. In the hot summer, it grew spindly stems which ranged from single stalks less than a foot high in poor conditions, to thick, rangy bushes up to three feet tall in excellent soil. The bright yellow flower gave it part of its name: the dozen inch-long needles which projected out from and below the head gave it the star nomenclature. It was a very nasty plant for animals or man to walk through in its ripened form, but it wasn't that aspect that made it so feared by horse owners.
When eaten in sufficient quantity, yellow star thistle caused irreversible neurological damage to equines, leaving them in a condition in which they would stand around with a vacant stare, head down and tongue hanging out. Like all animals, they instinctively avoided poisonous plants in pasture or rangeland provided that there was adequate other forage. However, if they were confined by fences, they would eat plants such as star thistle rather than go hungry, once the good plants had all been grazed down. Hay growers had a constant battle to keep the plant out of their fields, since clean hay could be sold at a premium to horse owners. People raising dairy or beef cattle didn't care if there were a few such weeds in the hay, since cows had no problem with it. But horse owners, knowing the possible damage and with considerable investment in money, training time, or emotion in their animals, were very upset if they purchased hay and found star thistle plants mixed with the alfalfa.