Pedicularis longiflora Rudolph var. tubiform is(KIotz.) Tsoog is a kind of annual weed spreaded widely on Qinghaixizang (Tibet) Plateau. According to the information afforded by the department of agricultural production, if this 晈eed occurs in highland barley (Hordeum vulgare) fields, the germination of seeds and normal growth of young sprout of highland barley around it would be inhibited.Three sets of experiments on the extracts of Pedicularis longiflora Rudolph var. tubiformis (Klotz.) Tsoog have been ca...