Kalmar "Genus Lactuca" tana nufin rarrabuwa a cikin haraji, wanda ya haɗa da rukuni na tsire-tsire waɗanda aka fi sani da letus. Halin nasa ne na dangin daisy, Asteraceae, kuma ya haɗa da nau'ikan letas da yawa waɗanda ake nomawa don abinci. Kalmar "lactuca" ta fito ne daga kalmar Latin don madara, saboda ruwan 'ya'yan itace mai madara da ake samu a cikin tushen waɗannan tsire-tsire.
