A large colony of tall plants with elongated yellow flower clusters and three-parted leaves is easy to spot and identify; you are looking at the common and lovely golden banner. The plants grow quickly after snow melt and by late spring large colonies are in bloom under aspens. Like so many plants that form large colonies, golden banner spreads from underground roots. Thermopsis montana enjoys cool, moist forests and is often surrounded by lush vegetation. Cured.. He flowers were commonly used by the natives as a source of yellow dye and were boiled in a tea as a cure for stomach ailments for people andhorses. The plant has toxic properties if ingested; symptoms of poisoning includevomiting, dizziness, and abdominal pain.