Malik F. T., Clement R. M., Gethin D. T., Kiernan M., Goral T., Griffiths P., Beynon D., Parker A. R., Hierarchical structures of cactus spines that aid in the directional movement of dew droplets, Philosophical Transactions of the Royal Society A, 2016, 374(2073):20160110, doi: 10.1098/rsta.2016.0110
The authors track droplet movement along the spines of Copiapoa gigantea, described in the paper as C. cinerea var. haseltoniana. Microscopy, labelling water with nanoparticles and imaging the stem interior allow them to discuss spine geometry and a possible route for water entry into the plant.