Stemflow represents the portion of precipitation routed by vegetation to the base of tree boles or plants stems. Van Stan and Allen (2020) (herein referred to as VS&A) is a mini review of studies that have attempted to quantify the infiltration area of stemflow once it has reached the soil surface, IT. More specifically, VS&A provide an overview of: (i) the ability of vegetation canopies to funnel rainfall; (ii) the various approaches used to estimate or measure the size of IT; (iii) the different soil properties that may influence the magnitude of IT, and (iv) the potential for and limitations to using dye and stable isotope tracers in IT research. The objectives of this commentary are to: (i) highlight and expand upon important points raised by VS&A in order to advance the understanding of the controls regulating the size of IT, and (ii) provide corrections to and clarification of prior IT results presented in VS&A. This commentary was written in conjunction with Project LinkA20045 of the international scientific collaboration program i-LINK+ 2018 funded by the Spanish National Research Council (CSIC). Peer reviewed