ODESSA, Texas (AP) _ Heavy rains this spring have spawned a bumper crop of rayless goldenrod, a shrub a that can mean death for grazing animals.

Doug Hardcastle, who leases a ranch near Odessa, says he lost 52 steers in one week to rayless goldenrod.

It took only days for the cattle to die a slow, trembling death after eating the poisonous plant, he said.

Odessa veterinarian Debra Gratehouse said there is no treatment for infection from rayless goldenrod.

The toxin's symptoms include trembling and stiffening of limbs and lack of coordination, and the animal then becomes ''hyperexcitable'' and dies, Ms. Gratehouse said.

Toxic plants are a fact of life in West Texas, but this year ranchers report more than usual because of the rains.

Researchers attacking the problem are using chemicals on test lots on an Ector County ranch, said Ron Hilliard, district conservationist with the U.S. Soil Conservation Service.

''We used three different chemicals and achieved up to 99 percent control,'' he said.

The most promising, still unlabeled but achieving almost total control, is expected to be released by Du Pont in early 1988 under the Escort trademark, Hilliard said.

It could prove a boon to ranchers resigned to moving their cattle from fields infested by the weed, which is not the most efficient use of the land, he said.

The half-shrub, which sprouts up to three feet high, grows in early spring and flowers in summer.

That's when the plant is at its most dangerous, Hilliard said. While the whole plant is poisonous green or dry, it lures livestock attracted to the green foliage and flowers early in the season before other feed is available.

And Hilliard said it doesn't take a great amount to be toxic - a 900-pound calf would need to eat only nine pounds of forage to be at risk.