Pion M, Spangenberg J, Simon A, Bindschedler S, Flury C, Chatelain A, Bshary R, Job D, Junier P. 2013. Bacterial farming by the fungus Morchella crassipes. Proceedings of the Royal Society B 280: 20132242.

Pirozynski KA, Malloch DW. 1975. The origin of land plants: A matter of mycotrophism. Biosystems 6: 153–64.

Pither J, Pickles BJ, Simard SW, Ordonez A, Williams JW. 2018. Below-ground biotic interactions moderated the postglacial range dynamics of trees. New Phytologist 220: 1148–160.

Policha T, Davis A, Barnadas M, Dentinger BT, Raguso RA, Roy BA. 2016. Disentangling visual and olfactory signals in mushroom-mimicking Dracula orchids using realistic three-dimensional printed flowers. New Phytologist 210: 1058–71.

Pollan M. 2018. How to Change Your Mind: The New Science of Psychedelics. London, UK: Penguin.

Pollan M. 2013. The Intelligent Plant. The New Yorker: michaelpollan.com/articles-archive/the-intelligent-plant/ [accessed October 29, 2019].

Popkin G. 2017. Bacteria Use Brainlike Bursts of Electricity to Communicate. Quanta: www.quantamagazine.org/bacteria-use-brainlike-bursts-of-electricity-to-communicate-20170905/ [accessed October 29, 2019].

Porada P, Weber B, Elbert W, Pöschl U, Kleidon A. 2014. Estimating impacts of lichens and bryophytes on global biogeochemical cycles. Global Biogeochemical Cycles 28: 71–85.

Potts SG, Biesmeijer JC, Kremen C, Neumann P, Schweiger O, Kunin WE. 2010. Global pollinator declines: trends, impacts and drivers. Trends in Ecology & Evolution 25: 345–53.

Poulsen M, Hu H, Li C, Chen Z, Xu L, Otani S, Nygaard S, Nobre T, Klaubauf S, Schindler PM, et al. 2014. Complementary symbiont contributions to plant decomposition in a fungus-farming termite. Proceedings of the National Academy of Sciences 111: 14500–505.