noun, plural: phytohemagglutinins
Phytohemagglutinins are lectins capable of causing agglutination of erythrocytes and leukocytes. They are extracted from common beans (Phaseolus vulgaris), white kidney beans, green beans, fava beans, etc. They have various physiological effects, one of which is causing mitogenic effects, especially on T lymphocytes.
Word origin: phyto- (plant) + hemagglutinin.
Variant: phytohaemagglutinin (British)
See also: mitogen