Datura metel
Of the possible means of transport by wind, water, bird or human agency, the authors dismiss immediately scenarios involving dispersal by wind or via bird droppings as wholly implausible: the seeds of "Datura metel" are not only heavy but also lack any specialised adaptation to wind dispersal such as a wing or a pappus, and the fruits of "Datura" are not juicy berries which invite consumption by birds [unlike those of, for example, the bird-disseminated "Atropa"]. The authors settle upon transport by water as by far the most likely mode and, of the two scenarios involving water, human-mediated transportation being the more probable, although not ruling out a scenario whereby the buoyant fruits (and seeds possibly remaining viable after prolonged immersion in salt water) of "Datura" might have been carried to India by ocean currents. Another possibility is that "Datura" capsules might have been rafted naturally across the ocean on floating clumps of vegetation dislodged from their original locations, in the manner noted by Renner et al. to have occurred in the case of certain other plant species.