n 1  cap  :  a large genus (the type of the family Plantaginaceae) of weeds that have narrow or elliptic leaves and very small inconspicuous flowers in close-bracted spikes or heads, comprise the plantains, and include the Old World fleawort (P. psyllium) and two other plants (P. indica and P. ovata) having indigestible and mucilaginous seeds used as a mild cathartic - see PSYLLIUM SEED   2  :  PLANTAIN .
 
 
 
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