Requirements for Floral Initiation of Los Angeles Xanthium

Science  20 Mar 1959:
Vol. 129, Issue 3351, pp. 780-781
DOI: 10.1126/science.129.3351.780


Cocklebur from the Los Angeles area was found to require more extensive short-day treatment for floral initiation than plants of the same species from the Chicago region. Data obtained by grafting the two regional types of cocklebur indicate that the leaves of the Los Angeles Xanthium produce a comparatively low amount of the flowering stimulus.