http://www.uni-kassel.de/fb19/plantphysiology/media/files/-2012--KUTSCHERA_BRIGGS_Root-phototropism_from-dogma-to-the-mechanism-of-blue-light-perception.pdf
Photo Credit: [http://www.biosci.ohio-state.edu/~plantbio/osu_pcmb/pcmb_lab_resources/pcmb101_activities/hormones/plnt_grth_hrmns_grav_roots.htm].
Hemp Biology and
Botany